#5 Point of Sale Machines
A study of accessibility issues and potential
design solutions for designers, procurement
officials, and consumers.
W. Bradley Fain, Ph.D.
June 2009
1
This monograph documents the results of research conducted in the Accessibility Evaluation Facility
(AEF) of the Georgia Tech Research Institute. The AEF has performed a series of accessibility
evaluations for both industry and government customers. Although information about the outcome of
specific evaluations has been withheld, the data presented in this monograph is based upon general
outcomes and lessons learned stemming from research conducted at the Georgia Tech Research
Institute.
For additional information about this monograph please contact:
Dr. Brad Fain
Georgia Tech Research Institute
ELSYS/HSID/HSEB Mail Code 0840
Atlanta, GA 30332-0840
Voice (404) 407-7261
Fax (404) 407-9261
brad.fain@gtri.gatech.edu
Table of Contents
Table of Contents ...................................................................................................................................... 3
List of Tables ............................................................................................................................................ 7
List of Figures ........................................................................................................................................... 8
Introduction............................................................................................................................................. 11
What is a point of sale machine? ........................................................................................................ 11
Why produce an accessible point of sale machine? ............................................................................ 11
What types of assistive technologies (AT) are commonly used with point of sale machines? .......... 12
Which guidelines apply to point of sale machines?............................................................................ 14
Americans with Disabilities Act Guidelines................................................................................... 14
Section 508 Guidelines ................................................................................................................... 15
Evaluation Methodologies ...................................................................................................................... 19
How do I define the goals of the evaluation? ..................................................................................... 20
How do I perform a task analysis? ..................................................................................................... 21
How do I develop a Method of Test? ................................................................................................. 23
Which evaluation techniques should I use? ........................................................................................ 23
How should I document the results of the evaluation? ....................................................................... 29
Accessibility Issues and Potential Solutions........................................................................................... 31
What are the common issues associated with physical access to the machine? ................................. 32
A clear path to the machine is not provided. .................................................................................. 32
Sufficient clear floor or ground space is not provided. .................................................................. 33
What are the common issues associated with reach and visibility? ................................................... 35
Some components of point of sale machines may be difficult for users with mobility impairments
to reach............................................................................................................................................ 35
Some components of point of sale machines may be difficult to see from a seated position. ....... 37
The required workflow forces users to change positions frequently. ............................................. 38
Some components are designed only for right-handed or left-handed use. .................................... 39
What are the common issues associated with labeling? ..................................................................... 40
Small icons and text are difficult for users with low vision to perceive......................................... 40
Raised or recessed lettering may be difficult to perceive. .............................................................. 42
Labels are not clearly associated with the components that they label. ......................................... 43
Information presented in text labels is not accessible to users with visual impairments. .............. 45
Icons used in place of text labels may be ambiguous. .................................................................... 47
Instructions may be difficult for users with cognitive impairments to understand. ....................... 49
What are the common issues associated with displays? ..................................................................... 52
Glare makes it difficult for some users to see the display. ............................................................. 52
LCD viewing angle limitations make it difficult to see the display from a seated position. .......... 54
Parallax may be a problem for seated users.................................................................................... 55
Small text and icons are difficult for users with low vision to perceive......................................... 56
Complex or inconsistent user interface screens may be difficult for users to understand. ............. 58
System time-outs may cause problems for some users. ................................................................. 59
What are the common issues associated with touchscreen interfaces? .............................................. 60
Touchscreen controls are not tactilely differentiable. ..................................................................... 60
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Touchscreen controls are easily activated and do not provide tactile feedback, often resulting in
unintentional control activations..................................................................................................... 61
A touchscreen placed for use by standing users may be difficult for users in wheelchairs to reach.
........................................................................................................................................................ 63
What are the common issues associated with pointing devices? ........................................................ 65
Users may have difficulty locating the pointing device. ................................................................ 65
Using pointing devices can be difficult for users with upper mobility impairments. ..................... 67
A free-moving cursor is inaccessible to some users with visual impairments. .............................. 70
Some touchpads do not respond to materials other than skin. ........................................................ 71
Grasping a stylus may be difficult for some users. ......................................................................... 73
What are the common issues associated with control panel buttons? ................................................ 74
Buttons mounted flush with the panel are difficult for users without vision or with low vision to
detect. .............................................................................................................................................. 74
Buttons that do not have sufficient contrast with the panel are difficult for users with low vision to
detect. .............................................................................................................................................. 76
Buttons are not identifiable as operable controls. ........................................................................... 78
Buttons that are small and close together may be difficult to differentiate or activate without
activating adjacent controls. ........................................................................................................... 80
Buttons that are all shaped the same or that do not have shapes corresponding to their functions
are more difficult for the blind to memorize and for the cognitively impaired to understand. ...... 82
Buttons do not provide a surface that facilitates button activation. ................................................ 84
Buttons requiring very little force to activate can increase the number of accidental activations. 86
Buttons requiring high levels of force to activate can pose difficulties for users with limited
strength. .......................................................................................................................................... 87
Chorded button operations can be difficult for users with upper mobility impairments. ............... 88
Buttons do not provide sufficient tactile feedback. ........................................................................ 89
Some types of buttons do not respond to touch from materials other than skin. ............................ 90
What are the common issues associated with control panel keypads? ............................................... 91
Keypads may lack nibs on the “5”, “F”, and “J” keys. ................................................................... 91
Non-standard numeric keypads pose a problem for some users..................................................... 93
The common methods of cursor advancement for numeric keypad text entry cause problems for
some users. ...................................................................................................................................... 95
What are the common issues associated with feedback? .................................................................... 96
The point of sale machine does not provide sufficient feedback to the user. ................................. 96
System response time to user input is slow. ................................................................................... 98
What are the common issues associated with indicator lights? .......................................................... 99
Information conveyed by indicator lights is not available to all users. .......................................... 99
Color coding is sometimes used as the sole means of conveying information. ........................... 101
Flashing lights can trigger seizures in some users. ....................................................................... 103
Overuse or misuse of indicator lights reduces their effectiveness. ............................................... 104
What are the common issues associated with audio output? ............................................................ 106
Information is presented only in audio form. ............................................................................... 106
The volume level is insufficient. .................................................................................................. 108
Ambient sound from the environment interferes with the user’s ability to hear audio output. .... 109
Non-verbal audio output is not meaningful. ................................................................................. 110
Voice output is difficult to understand due to poor sound quality or interference. ...................... 111
4
Voice output is not repeated. ........................................................................................................ 112
Audio output via speakers may be inappropriate due to privacy concerns. ................................. 113
What are the common issues associated with headphone jacks? ..................................................... 115
No headphone jack is provided on the device. ............................................................................. 115
Locating the headphone jack may be difficult for users with visual impairments. ...................... 116
The headphone jack does not use a standard connector. .............................................................. 118
Users may have difficulty inserting a plug into a headphone jack. .............................................. 119
The placement of the headphone jack allows the headphone cord to interfere with use of the
machine. ........................................................................................................................................ 120
What are the common issues associated with barcode readers? ....................................................... 122
Some users may have difficulty orienting a product properly for scanning. ................................ 122
Large and/or heavy products can be difficult for some users to scan. .......................................... 124
Grasping and operating a handheld barcode reader may be difficult for some users. .................. 126
Insufficient feedback is provided when a product is scanned. ..................................................... 128
Audio output from nearby machines may cause confusion during scanning. .............................. 130
What are the common issues associated with scales? ...................................................................... 132
Users may have difficulty locating the scale. ............................................................................... 132
Users may have difficulty knowing that the scale is ready for use. ............................................. 134
Users may have difficulty placing an item within the bounds of the scale. ................................. 135
The device does not provide sufficient feedback about the scale’s measurement. ...................... 137
What are the common issues associated with the bagging area? ...................................................... 139
The bagging area is not designed to accommodate large or heavy items. .................................... 139
The bagging area may generate confusing or spurious errors. ..................................................... 141
Users are not sufficiently notified when items remain in the bagging area.................................. 142
What are the common issues associated with the bill acceptor? ...................................................... 143
Users may have difficulty locating the bill acceptor. ................................................................... 143
Determining the proper orientation for inserting bills may be difficult for some users. .............. 145
Clear feedback on the inserted denomination and the outstanding balance is not provided. ....... 147
Clear feedback is not provided when a bill is rejected. ................................................................ 148
What are the common issues associated with the coin acceptor? ..................................................... 149
Users may have difficulty locating the coin acceptor. .................................................................. 149
Users are required to insert coins before inserting bills. .............................................................. 151
Inserting coins into a coin slot requires fine motor control. ......................................................... 152
Clear feedback on the inserted denomination and the outstanding balance is not provided. ....... 153
Clear feedback is not provided when a coin is rejected................................................................ 154
What are the common issues associated with card readers? ............................................................. 155
Users may have difficulty locating the card reader. ..................................................................... 155
Determining the proper orientation for inserting or swiping a card may be difficult. .................. 157
Users lacking fine motor control may have difficultly aligning and inserting a card. ................. 159
Users may have difficulty swiping cards through the full length of the card reader slot. ............ 161
Use of multiple user interfaces may cause problems for users. .................................................... 163
The card reader does not eject the card far enough for users to grasp it. ..................................... 164
Insufficient feedback is provided when a user forgets to retrieve a card. .................................... 166
What are the common issues associated with the signature area? .................................................... 167
Users may not be sufficiently notified that input is required in the signature area. ..................... 167
Users may have difficulty locating the signature area. ................................................................. 168
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Users may have difficulty determining the boundaries of the signature area. .............................. 170
Users may have difficulty aligning their signatures within the signature area. ............................ 172
What are the common issues associated with output areas? ............................................................. 173
Users may have difficulty locating output areas. .......................................................................... 173
Users are not sufficiently notified when outputs are present in the output area. .......................... 175
Users have difficulty retrieving outputs from the output area. ..................................................... 177
What are the common issues associated with the writing and temporary storage areas? ................. 179
No space for writing or temporarily placing belongings is provided. .......................................... 179
The storage or writing area is too high or too low to be accessible to all users. .......................... 181
What are the common issues associated with the supplies area? ..................................................... 182
Users may have difficulty locating the supplies area. .................................................................. 182
Doors and covers make it difficult for users to retrieve supplies. ................................................ 184
The design of the supplies area makes it difficult for users to reach or grasp the supplies. ......... 186
What are the common issues associated with the trash receptacle? ................................................. 188
Locating the trash receptacle may be difficult for some users. .................................................... 188
If the trash receptacle is covered, users may have difficulty depositing trash. ............................ 190
References............................................................................................................................................. 192
Appendix A: Checklist Evaluation ....................................................................................................... 193
6
List of Tables
Table 1: Potentially Applicable Section 508 Standards. ........................................................................ 15
7
List of Figures
Figure 1: Point of sale machine. ............................................................................................................. 11
Figure 2: Reaching aid. ........................................................................................................................... 13
Figure 3: Minimum clear floor space for wheelchairs............................................................................ 33
Figure 4: Wheelchair turning space dimensions. .................................................................................... 34
Figure 5: The touchscreen of a point of sale machine is too high, causing reach problems for a seated
user. ......................................................................................................................................................... 35
Figure 6: The touchscreen of a point of sale machine is low enough for a seated user to reach it. ....... 36
Figure 7: Very small labels and icons on a point of sale machine keypad. ............................................ 40
Figure 8: Large labels and icons on a point of sale machine keypad. .................................................... 41
Figure 9: Icons are not clearly associated with the buttons that they label. ........................................... 43
Figure 10: Icons are clearly associated (by proximity) with the buttons that they label. ....................... 44
Figure 11: No tactile labels are provided on a point of sale machine keypad. ....................................... 45
Figure 12: Braille labeling on the “Enter” key on a point of sale machine keypad. .............................. 46
Figure 13: Buttons on a point of sale machine are labeled only with ambiguous icons......................... 47
Figure 14: Buttons on a point of sale machine have text labels supplemented with icons..................... 48
Figure 15: Unnecessarily complex instructions on the display of a point of sale machine. ................... 49
Figure 16: Simple instructions with an accompanying illustration on the display of a point of sale
machine. .................................................................................................................................................. 50
Figure 17: The angle of the display results in glare for a seated user. ................................................... 52
Figure 18: An adjustable display allows a seated user to adjust the display angle to reduce glare. ....... 53
Figure 19: A hood shields the display from overhead lights, reducing glare for seated users. .............. 53
Figure 20: Small text and icons are shown on the display of a point of sale machine. .......................... 56
Figure 21: Large text and icons are shown on the display of a point of sale machine. .......................... 57
Figure 22: Touchscreen numeric keypad buttons that are too small and too close together. ................. 61
Figure 23: Touchscreen numeric keypad buttons that are larger and more widely spaced. ................... 62
Figure 24: A user in a wheelchair having difficulty reaching the touchscreen. ..................................... 63
Figure 25: An auxiliary control interface placed within reach of a user in a wheelchair. ...................... 64
Figure 26: A stylus that is tethered to the point of sale machine. ........................................................... 65
Figure 27: On-screen controls are small and require precise movements to activate. ........................... 67
Figure 28: On-screen controls are large, reducing the degree of precision required. ............................. 68
Figure 29: An auxiliary control interface provides an alternative to a free-moving cursor. .................. 70
Figure 30: Attempting to interact with a touchpad with a pencil eraser. ................................................ 71
Figure 31: The stylus is the size of a standard pen and has a rubbery grip. ........................................... 73
Figure 32: Buttons on a control panel are flush with the panel surface. ................................................ 74
Figure 33: Buttons on a control panel are raised above the panel surface. ............................................ 75
Figure 34: Buttons on a control panel have very little contrast with the control panel surface. ............ 76
Figure 35: Buttons on a control panel have high contrast with the control panel surface. ..................... 77
Figure 36: A stylized button is not identifiable as an operable control. ................................................. 78
Figure 37: Design of the button and accompanying text help to identify the button as an operable
control. .................................................................................................................................................... 79
Figure 38: Buttons on a control panel are very small and close together. .............................................. 80
Figure 39: Buttons on a control panel are larger and more widely spaced. ............................................ 81
Figure 40: Buttons on a control panel are all shaped identically. ........................................................... 82
8
Figure 41: Buttons on a control panel are grouped and distinguished by size, shape, and color. .......... 83
Figure 42: Buttons on a control panel are slick and convex. .................................................................. 84
Figure 43: Buttons on a control panel a concave and made from a high friction material. .................... 84
Figure 44: Low activation force for a button results in inadvertent activations. .................................... 86
Figure 45: The “5” key on the numeric keypad lacks a nib.................................................................... 91
Figure 46: A nib is provided on the “5” key of the numeric keypad. ..................................................... 92
Figure 47: A non-standard numeric keypad layout. ............................................................................... 93
Figure 48: A standard numeric keypad layout. ....................................................................................... 93
Figure 49: A confirmation screen with a “Back” button facilitates recovery from errors. .................... 98
Figure 50: An indicator light is placed out of sight for a seated user. .................................................... 99
Figure 51: An indicator light is placed so that a seated user can see it. ............................................... 100
Figure 52: A single light illuminates red or green to indicate status. ................................................... 101
Figure 53: Separate red and green lights and redundant text indicate status. ...................................... 102
Figure 54: Overuse of indicator lights reduces their effectiveness for attracting attention or
communicating information.................................................................................................................. 104
Figure 55: Instructions are provided to the user only in audio form. ................................................... 106
Figure 56: Instructions are provided to the user as audio and as text. .................................................. 107
Figure 57: A volume knob is provided to allow the user to adjust the output volume. ........................ 108
Figure 58: A volume knob is provided to allow the user to adjust the output volume. ........................ 109
Figure 59: Potentially sensitive audio is output through speakers. ...................................................... 113
Figure 60: A headphone jack is provided for private listening. ........................................................... 113
Figure 61: A headphone jack is provided for private listening. ........................................................... 115
Figure 62: The headphone jack is located in an obscure location on the device. ................................. 116
Figure 63: The headphone jack is located in a prominent location on the device. ............................... 116
Figure 64: The headphone jack location allows the cord to interfere with use of the machine. .......... 120
Figure 65: The headphone jack location prevents the cord from interfering with use of the machine. 121
Figure 66: The barcode reader only scans one side of an item at a time. ............................................. 122
Figure 67: The barcode reader only scans two sides of an item at a time. ........................................... 123
Figure 68: A large item is difficult to scan using an integrated barcode reader. .................................. 124
Figure 69: A handheld barcode reader makes it easier to scan large items. ......................................... 124
Figure 70: A handheld barcode reader without a handle is difficult to grasp....................................... 126
Figure 71: A handheld barcode reader with a handle is easier to grasp. .............................................. 127
Figure 72: No feedback is provided when an item is scanned. ............................................................ 128
Figure 73: Visual and auditory feedback is provided when an item is scanned. .................................. 129
Figure 74: Directing audio output toward the user helps users identify the source of the audio. ........ 130
Figure 75: A headphone jack is provided for private listening. ........................................................... 131
Figure 76: The scale is not tactilely discernible. .................................................................................. 132
Figure 77: Visual and tactile cues increase the discernability of the scale. .......................................... 133
Figure 78: The bounds of the scale are not clearly defined with visual and tactile cues. ..................... 135
Figure 79: The bounds of the scale are clearly defined with visual and tactile cues. ........................... 136
Figure 80: Feedback about the scale’s measurement is not provided audibly. .................................... 137
Figure 81: Feedback about the scale’s measurement is provided audibly. ........................................... 138
Figure 82: The bagging area does not provide space to place large items. .......................................... 139
Figure 83: The device provides a “skip bagging” option. .................................................................... 140
Figure 84: The bagging area provides space to place large items. ....................................................... 140
Figure 85: The bill acceptor is difficult to discern visually and tactilely. ............................................ 143
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Figure 86: The bill acceptor is designed to be visually and tactilely discernible. ................................ 144
Figure 87: No cues are provided on the bill acceptor to indicate the proper insertion orientation. ..... 145
Figure 88: A graphic on the bill acceptor shows the proper insertion orientation. .............................. 146
Figure 89: The coin acceptor is difficult to discern visually and tactilely. ........................................... 149
Figure 90: A label and a recessed area around the coin slot increase visual and tactile discernability.
.............................................................................................................................................................. 150
Figure 91: A funnel into which coins can be dropped makes it easier to insert coins.......................... 152
Figure 92: The card reader is unlabelled and has poor visual contrast. ................................................ 155
Figure 93: The card reader is labeled and has good visual contrast. .................................................... 156
Figure 94: The proper orientation for swiping a card is not shown...................................................... 157
Figure 95: A label shows the proper orientation for swiping a card. ................................................... 158
Figure 96: The card slot is not designed to guide the card into the slot. .............................................. 159
Figure 97: The card slot is designed to help guide the card into the slot. ............................................ 159
Figure 98: The card reader slot is long and is oriented horizontally. ................................................... 161
Figure 99: The card reader slot is short and is oriented vertically. ....................................................... 162
Figure 100: The card reader does not eject the card far enough for the user to grasp it. ..................... 164
Figure 101: The card reader ejects the card far enough for the user to grasp it. .................................. 164
Figure 102: The signature area is not tactilely discernible. .................................................................. 168
Figure 103: A raised edge around the signature area improves tactile discernability. ......................... 169
Figure 104: The signature area only fills a portion of the screen. ........................................................ 170
Figure 105: The signature area fills the entire screen. .......................................................................... 171
Figure 106: Output areas are located in several different locations on the device. .............................. 173
Figure 107: All of the output areas on the device are collocated. ........................................................ 174
Figure 108: Change is hidden behind a door, and cash is not clearly visible in the cash tray. ............ 175
Figure 109: Outputs are clearly visible within the output area. ............................................................ 176
Figure 110: Cash and change are difficult to retrieve from the output areas. ...................................... 177
Figure 111: Cash and change are easy to grasp and remove from the output areas. ............................ 178
Figure 112: An appropriate area for writing or placing belongings is provided. ................................. 179
Figure 113: The supplies area is unlabeled and not prominently located............................................. 182
Figure 114: The supplies area is clearly labeled and prominently located. .......................................... 183
Figure 115: Access to the supplies is obstructed by a door. ................................................................. 184
Figure 116: Access to the supplies area is unobstructed by a door or cover. ....................................... 185
Figure 117: The opening to the supplies area is too small. .................................................................. 186
Figure 118: The opening to the supplies area is large enough to accommodate a hand or reaching aid.
.............................................................................................................................................................. 187
Figure 119: The trash slot is located on the side of the machine and is not clearly labeled. ................ 188
Figure 120: The trash receptacle is located on the front of the machine and is clearly labeled. .......... 189
Figure 121: The trash receptacle is covered by a door. ........................................................................ 190
Figure 122: The trash receptacle is an uncovered, open slot. ............................................................... 191
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Introduction
What is a point of sale machine?
A point of sale (POS) (Figure 1) machine is a type of interactive
device that allows customers of a business to conduct self-service
financial transactions. Examples include credit card payment terminals,
retail store self-checkout stations, movie theater ticket machines,
machines used for ordering food at convenience stores or quick service
restaurants, airport check-in machines, and gas station pay-at-the-pump
systems. The number of POS machines in use is increasing, and the
range of transactions handled by these machines continues to expand.
POS machines can reduce transaction times, enhance privacy,
and provide greater convenience for many shoppers. However, as the
Figure 1: Point of sale machine.
reliance on POS machines to conduct business with the public increases,
the importance of providing POS machines that are accessible to people with disabilities increases as
well. POS machines pose a number of accessibility issues. The physical design of these types of
devices, which are often large and designed to be used by users in a standing position, can result in
difficulties for users with lower mobility impairments. Interacting with the various components of
POS machines can be difficult for users with upper mobility impairments, and the lack of
standardization in the layout of components among machines can make create difficulty for users with
visual impairments. POS machines sometimes have complex user interfaces that support a diverse
range of functions, and the complexity of the interface can pose problems for users with cognitive
impairments. Other aspects of the design of user interfaces for POS machines can cause problems for
users with impaired vision or hearing, as well.
Why produce an accessible point of sale machine?
There are three major reasons why a company might be interested in designing an accessible
point of sale machine. First, companies may decide to market the accessibility features of the device to
help discriminate it from the competition. Accessibility can become a key market discriminator in a
group of products with similar features. Furthermore, increased accessibility often leads to increases in
the usability of the device for all users, another marketable benefit. Second, companies may produce
accessible point of sale machines in order to be in conformance with the standards of Section 508 of
the Rehabilitation Act so that they can effectively market their products to the Federal Government.
Section 508 of the Rehabilitation Act requires Federal departments and agencies that develop, procure,
maintain, or use electronic and information technology to ensure that Federal employees and members
of the public with disabilities have access to and use of information and data, comparable to that of the
employees and members of the public without disabilities - unless it is an undue burden to do so.
Finally, companies might produce an accessible point of sale machine in order to broaden their market
to include additional users with functional limitations.
11
What types of assistive technologies (AT) are commonly used with point
of sale machines?
Assistive technologies are pieces of equipment or software that are used to increase the
capabilities of people with disabilities. The following is a list of AT that people might use to aid in
interacting with point of sale machines:
Magnifying glass - A magnifying glass or magnifier is a handheld lens that is used to increase
the size of an image. Typical magnification powers range from 2x to 10x. Some magnifying glasses
have an integrated light, which may increase visibility for some users.
o
o
o
Used by: Magnifiers are used by people with low vision, who may require larger text and
images to be able to read and understand content.
Used for: On a point of sale machine, magnifiers are used to read labels and displays.
AT impact on point of sale machine operation: Magnifiers allow people with low vision
to obtain information that is presented in a text size that is otherwise too small for them to
read. The use of a magnifier requires the user to get very close to the object of interest. On
a point of sale machine, this sometimes requires the user to assume an uncomfortable
position. The design of the device and the placement of the item to be viewed may prevent
a user from getting close enough with a magnifier to read the information of interest.
Manipulation stick - A manipulation stick is a rod, typically a wooden dowel, used as an aid
to increase a user’s reach or strength. Common end attachments are rubber tips and hooks. Rubber
tips are used to press against an object (for example, to close a cupboard door or activate a switch).
Hooks are used to pick things up or to pull objects (for example, to open a drawer). It is not
uncommon for a manipulation stick to have a rubber tip on one end and a hook on the other. Many
people who use manipulation sticks have both a short stick and a long stick.
o
o
o
Used by: Manipulation sticks are typically used by individuals who have limited strength in
their hands or arms, or who have limited reach capability (i.e., people with upper mobility
impairments).
Used for: A manipulation stick can facilitate many tasks associated with use of a point of
sale machine. Common tasks include activating controls, and inserting or retrieving cards,
cash, coins, and receipts.
AT impact on point of sale machine operation: Manipulation sticks increase a user’s
reach. The manipulation stick can also increase a user’s leverage. Manipulation sticks are
sometimes used in combination with an electric wheelchair. The user positions the stick,
and then uses the force generated by the wheelchair’s motor to apply the necessary pressure
to activate a control or open a drawer. Manipulation sticks are only useful when they are
available to the user. Users who have both a short stick and a long stick may not carry
both, and may find that they need the one that they don’t have. Someone with a long
manipulation stick may find that the stick is too long to use easily. For example, to use the
longer stick, the user must often be at a further distance from the object being manipulated,
which means that a lot of extra maneuvering may be required. Some environments will not
provide enough room for a user to obtain the necessary distance, which may mean the user
will be unable to use the stick. A greater degree of fine motor control may also be required
to use a longer stick. Additionally, the ends of the stick may not be suitable for use with
12
some devices. For example, the rubber end of the manipulation stick may be too large to
activate some controls, or the gap on the hook may be insufficient to grab onto some
objects with adequate leverage.
Reaching aid - A reaching aid is a 1 to 2 foot long device with a trigger handle used to open
and close the end for the purpose of grasping objects that are difficult to reach. Figure 2 shows a
typical reaching aid.
o
o
o
Used by: Reaching aids are often used by people who use a wheelchair or who have an
upper mobility impairment that limits their reach distance.
Used for: On a point of sale machine, reaching aids are used to insert and retrieve cards,
cash, coins, and receipts, and to manipulate items for scanning and bagging.
AT impact on point of sale machine operation: Reaching aids enhance the ability of
people with limited reach to perform point of sale machine tasks that require the user to
reach. Such tasks may include scanning and bagging items and inserting and retrieving
payment and receipts.
Figure 2: Reaching aid.
Scooter - A scooter is a motorized mobility device. Unlike a traditional wheelchair, the seat of
a scooter can rotate left and right, approximately 90 degrees in either direction, giving the user more
flexibility to interact with the environment.
o
o
o
Used by: A scooter is typically used by individuals who have restricted use of their legs
(i.e., people with lower mobility impairments).
Used for: A scooter is not assistive technology to aid interaction with a device. Rather, a
scooter is AT that users of a device may require that may inhibit their access to the device.
AT impact on point of sale machine operation: The same limitations that apply to
wheelchairs (described below) apply to scooters; however, scooter users typically have
greater physical mobility, and can move forward on their seats or lean forward, which
increases their reach capability over that of some wheelchair users. Whereas wheelchairs
have a fixed seat, the rotating seat of a scooter allows the user to face the device without
having the bulk of the mobility aid between the person and the device. This extra mobility
increases the user’s reach, and removes barriers created when approaching parallel to a
device (see discussion of wheelchair impact, below).
Wheelchair - A wheelchair is a device used for mobility. Both manual and electric models are
available. Some electric wheelchairs allow the user to raise and lower the height of the seat. The seat
itself is fixed in a forward facing position.
13
o
o
o
Used by: A wheelchair is typically used by individuals who have restricted use of their legs
(i.e., people with lower mobility impairments).
Used for: A wheelchair is not assistive technology to aid interaction with a device. Rather,
a wheelchair is AT that users of a device may require that may inhibit their access to the
device.
AT impact on point of sale machine operation: Point of sale machines are typically
designed to be used by an individual of average height standing in front of the device.
Wheelchair users are in a seated position, with an eye level considerably lower than that of
a standing person. As a result, they may have difficulty seeing the displays and labels on
the device, and may have difficulty reaching some device components. Wheelchair users
vary in how they prefer to approach devices for interaction. Many people prefer a forward
approach (with the chair oriented such that they are facing the device), but this approach
increases the user’s distance from the device, exacerbating the limitations already in place
from being in a seated position. Others prefer to approach parallel to the device, but this
approach also has problems: if the user approaches with his non-dominant hand closest to
the device, he has to reach further to use his dominant hand, but if the user approaches with
his dominant hand closest to the device, he may need to put his arm in an awkward position
in order to manipulate the controls. Furthermore, many people in wheelchairs are unable to
move forward on their seats, and some cannot lean their upper bodies forward, limiting
their reach abilities even more. The design of point of sale machines and their placement in
the environment may favor (or necessitate) one approach or the other.
Which guidelines apply to point of sale machines?
Americans with Disabilities Act Guidelines
The Americans with Disabilities Act (ADA) guidelines are published in conjunction with the
Architectural Barriers Act (ABA) guidelines as the ADA and ABA Accessibility Guidelines. The
ADA guidelines apply to facilities in the private sector, and to state and local government facilities; the
ABA guidelines apply to federally funded facilities. The ADA-ABA guidelines contain guidance that
applies to automatic teller machines and fare machines and specifically excludes other types of
interactive transaction machines from the scope of the guidance. However, the ADA-ABA guidelines
represent best practices for accessibility, and are used in this document as recommendations for
designing accessible point of sale machines. The complete ADA-ABA accessibility guidelines can be
found at the link above; the following sections of the guidelines are the most relevant to the design and
installation of point of sale machines.
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220 Automatic Teller Machines and Fare Machines
302 Floor or Ground Surfaces
303 Changes in Level
304 Turning Space
305 Clear Floor or Ground Space
306 Knee and Toe Clearance
308 Reach Ranges
309 Operable Parts
403 Walking Surfaces
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703.3 Braille
707 Automatic Teller Machines and Fare Machines
811 Storage
904.3.3 Check Writing Surfaces
904.5.1 Self-Service Shelves and Dispensing Devices
Section 508 Guidelines
Section 508 applies specifically to federal departments and agencies, although various state and
local governments have also adopted legislation based on Section 508. Section 508 does not apply to
procurement in the private sector. However, the Section 508 technical standards represent best
practices for accessibility, and are used in this document as recommendations for designing accessible
point of sale machines.
Table 1, below, lists Section 508 guidelines that may apply to point of sale machines,
depending on the design features of the device and the circumstances surrounding its use.
Table 1: Potentially Applicable Section 508 Standards.
508 Standard that may apply
Situations in which it could apply
1194.25(a) Self contained products shall be usable by
people with disabilities without requiring an end-user to
attach assistive technology to the product. Personal
headsets for private listening are not assistive technology.
This standard applies if the device requires
users to attach items of assistive
technology (excepting audio headsets) to
the device in order to access it.
1194.25(b) When a timed response is required, the user
shall be alerted and given sufficient time to indicate more
time is required.
This standard applies if there any
instances where the device limits the time
allowed for users to perform an action or
provide a response.
1194.25(c) Where a product utilizes touchscreens or
contact-sensitive controls, an input method shall be
provided that complies with 1194.23(k)(1) through (4).
This standard applies if the device has a
touchscreen or other non-mechanical,
contact sensitive controls.
Standard 1194.23(k)(3) only applies if key
repeat is supported (e.g., keys repeat entry
when pressed for a specified period of
1194.23(k)(2) Controls and keys shall be operable with time).
one hand and shall not require tight grasping, pinching,
or twisting of the wrist. The force required to activate Note: A best practice would be to apply
1194.23(k) to all mechanically operated
controls and keys shall be 5 lbs. (22.2 N) maximum.
controls such as buttons, knobs, and
switches, whether or not 1194.25(c)
1194.23(k)(3) If key repeat is supported, the delay
before repeat shall be adjustable to at least 2 seconds. applies. Some believe this approach
reflects the true intent of the guidelines.
Key repeat rate shall be adjustable to 2 seconds per
character.
1194.23(k)(1) Controls and keys shall be tactilely
discernible without activating the controls or keys.
1194.23(k)(4) The status of all locking or toggle
controls or keys shall be visually discernible, and
15
508 Standard that may apply
Situations in which it could apply
discernible either through touch or sound.
1194.25(d) When biometric forms of user identification or
control are used, an alternative form of identification or
activation, which does not require the user to possess
particular biological characteristics, shall also be provided.
This standard applies if the device uses
biometric forms of user identification,
such as a fingerprint scanner or a retinal
scanner.
1194.25(e) When products provide auditory output, the
audio signal shall be provided at a standard signal level
through an industry standard connector that will allow for
private listening. The product must provide the ability to
interrupt, pause, and restart the audio at anytime.
This standard applies if the device
provides voice output.
1194.25(f) When products deliver voice output in a public This standard applies if the device
area, incremental volume control shall be provided with
provides voice output.
output amplification up to a level of at least 65 dB. Where
the ambient noise level of the environment is above 45 dB,
a volume gain of at least 20 dB above the ambient level
shall be user selectable. A function shall be provided to
automatically reset the volume to the default level after
every use.
1194.25(g) Color coding shall not be used as the only
means of conveying information, indicating an action,
prompting a response, or distinguishing a visual element.
This standard applies if color coding is
used to convey information on the device.
1194.25(h) When a product permits a user to adjust color This standard applies if the device’s
and contrast settings, a range of color selections capable of display uses color and the device permits
producing a variety of contrast levels shall be provided.
the user to adjust color and contrast
settings.
1194.25(i) Products shall be designed to avoid causing the This standard applies if the device’s
screen to flicker with a frequency greater than 2 Hz and
display or elements on the display flash
lower than 55 Hz.
with a frequency between 2 and 55 Hz.
1194.25(j)(1) Products which are freestanding, nonportable, and intended to be used in one location and
which have operable controls shall comply with the
following: The position of any operable control shall be
determined with respect to a vertical plane, which is 48
inches in length, centered on the operable control, and at
the maximum protrusion of the product within the 48 inch
length on products which are freestanding, non-portable,
and intended to be used in one location and which have
operable controls.
This standard applies if the device is
freestanding, non-portable, and intended
to be used in one location and has
operable controls.
1194.25(j)(2) Products which are freestanding, nonportable, and intended to be used in one location and
which have operable controls shall comply with the
following: Where any operable control is 10 inches or less
This standard applies if the device is
freestanding, non-portable, and intended
to be used in one location and has
operable controls.
16
508 Standard that may apply
Situations in which it could apply
behind the reference plane, the height shall be 54 inches
maximum and 15 inches minimum above the floor.
Note that this guideline was based on a
previous version of the ADA guidelines;
the most recent revision of the ADA
guidelines reduced the height from 54
inches to 48 inches.
1194.25(j)(3) Products which are freestanding, nonportable, and intended to be used in one location and
which have operable controls shall comply with the
following: Where any operable control is more than 10
inches and not more than 24 inches behind the reference
plane, the height shall be 46 inches maximum and 15
inches minimum above the floor.
This standard applies if the device is
freestanding, non-portable, and intended
to be used in one location and has
operable controls.
1194.25(j)(4) Products which are freestanding, nonportable, and intended to be used in one location and
which have operable controls shall comply with the
following: Operable controls shall not be more than 24
inches behind the reference plane.
This standard applies if the device is
freestanding, non-portable, and intended
to be used in one location and has
operable controls.
1194.31(a) At least one mode of operation and information This standard always applies.
retrieval that does not require user vision shall be
provided, or support for assistive technology used by
people who are blind or visually impaired shall be
provided.
1194.31(b) At least one mode of operation and information This standard always applies.
retrieval that does not require visual acuity greater than
20/70 shall be provided in audio and enlarged print output
working together or independently, or support for assistive
technology used by people who are visually impaired shall
be provided.
1194.31(c) At least one mode of operation and information This standard always applies.
retrieval that does not require user hearing shall be
provided, or support for assistive technology used by
people who are deaf or hard of hearing shall be provided.
1194.31(d) Where audio information is important for the
use of a product, at least one mode of operation and
information retrieval shall be provided in an enhanced
auditory fashion, or support for assistive hearing devices
shall be provided.
This standard applies if audio information
is important for use of the device. For
example, audio information (speech
output, etc.) for which there is not a
redundant visual alternative would be
covered by this standard.
1194.31(e) At least one mode of operation and information This standard always applies.
retrieval that does not require user speech shall be
provided, or support for assistive technology used by
17
508 Standard that may apply
Situations in which it could apply
people with disabilities shall be provided.
1194.31(f) At least one mode of operation and information This standard always applies.
retrieval that does not require fine motor control or
simultaneous actions and that is operable with limited
reach and strength shall be provided.
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Evaluation Methodologies
There are two basic methods of acquiring information about human performance: direct
measurement and derived assessments. If your goal is to evaluate the ability of a specific individual to
perform in a technological system, then you place that individual in the system, give him or her a
representative series of tasks to complete, and observe his or her performance. This direct
measurement approach allows you to collect very good data about the ability of a single individual to
interact with a given device, although the findings may not generalize to a larger population. More
robust direct measurement studies adopt effective sampling strategies. By testing a diverse and
representative group of users, the evaluator can generalize findings to a larger population segment with
much better accuracy. Effective sampling for accessibility evaluations can be very challenging. Not
only are there a variety of disability types to consider, but a variety of functional abilities within each
disability type to consider as well.
There are eight major categories of functional limitations that can be addressed in an
accessibility evaluation: upper mobility impairments, lower mobility impairments, hardness of hearing,
deafness, low vision, blindness, speech impairments, and cognitive impairments. Within each category
of functional limitation there are a variety of subtypes and levels of disability. For example, in the
upper mobility category, someone may have a hand tremor that impacts fine motor control, a muscular
abnormality that impacts strength, or an injury that limits reach. A user’s level of experience may also
have a significant impact on the outcome of the evaluation. The accessibility problems experienced by
someone who has been blind since birth may be significantly different than the accessibility problems
experienced by someone who has recently lost his or her vision.
Derived assessment methods, such as functional assessments, checklist evaluations, or expert
inspections, do not seek to measure human performance directly. Instead, such techniques are used to
determine the extent to which a device meets formal or informal guidelines that have been associated
with desired human performance objectives. A checklist evaluation, also known as a heuristic
evaluation, is employed where a considerable body of knowledge about a specific domain of human
performance relative to the product of interest exists (Nielsen, 1994). For example, a significant
amount of research related to the readability of computer displays under normal lighting conditions has
been performed. Researchers have analyzed the existing data and developed design guidance for the
selection of a font size for important information on computer displays that applies to users with
normal or correctable vision. Instead of performing detailed user-in-the-loop test procedures,
evaluators can simply measure the font size and viewing distance, and compare the results to
established design guidelines.
Occasionally, our knowledge about a specific domain is either incomplete, or the results of
previous research are so ambiguous or conflicting, that the development of useful guidelines is
impossible. Also, it may be impossible to formulate design guidelines without knowledge of the
operational environment of the device. For example, many studies have expressed the importance of
providing sufficient contrast on labels or other display items that must be discernable from the
background. However, it is very difficult to specify a minimum contrast ratio without knowing details
about the device and the context in which it will be used. The contrast ratio of a label must be greater
if the label is to be read outdoors as opposed to a label that will only be read indoors. Also, the size,
coloration, and position of the control can impact contrast requirements. Therefore, it may be
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impossible to develop a design guideline that is specific enough to objectively test. In such cases,
other methods of evaluating accessibility must be employed or the expertise of the evaluator must be
relied upon.
Given the challenges of sampling from a diverse population and our somewhat limited
knowledge of designing for people with disabilities, it is necessary to combine data from both direct
measurement and derived assessment evaluation techniques to obtain the desired degree of confidence
in the evaluation results. Gaps in our knowledge in designing for people with disabilities can be
addressed by performing user testing. Similarly, the sampling issues associated with human
performance testing for accessibility can be addressed by using the derived assessment results to
eliminate the need to test some populations and focus the assessment on others.
A variety of evaluation techniques and methodologies are available to the evaluator interested
in measuring accessibility. However, there are five main high-level activities common to all
accessibility evaluations:
 Define evaluation goals
 Perform a task analysis
 Develop a Method of Test
 Perform the evaluations
 Document the results
How do I define the goals of the evaluation?
It is critical to the success of the evaluation effort to determine the specific goals of the
evaluation and the intended audience of the test data prior to designing the data collection method.
Failure to consider the goal of the evaluation may result in incomplete data or wasted efforts. If the
goal of the evaluation is to measure conformance with a specific set of requirements, such as the
Section 508 standards, then the accessibility evaluation should focus on checklist evaluation
techniques supported by user testing when needed. If the evaluation goal is to determine if a particular
device is accessible to a particular individual, then the evaluation can focus on user testing supported
by a functional assessment.
Evaluators may need to know which device among several similar devices is most accessible.
If asked to choose among several different options, evaluators should use empirical evidence of
accessibility whenever possible. For example, a variety of different desktop printers are available from
a variety of different manufactures. Each device can differ in terms of the accessibility features they
provide and the accessibility barriers inherent in the designs of the equipment. An accessibility
evaluation can assist someone in choosing a device that is most accessible to a given individual or a
class of individuals. In order to measure general accessibility and compare the results among multiple
products, both checklist evaluations and user testing are important.
Evaluators may also need to know how well the device conforms to a specific set of guidelines
or technical requirements. Commonly, evaluations are performed to measure the conformance with
the Section 508 standards for the purpose of preparing a Voluntary Product Accessibility Template
(VPAT). A VPAT is used to allow companies to document and communicate the accessibility of a
particular product to a potential Federal Government customer. An accessibility evaluation for this
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purpose relies heavily on the checklist evaluation approach; however, user testing may be required to
document conformance with some technical requirements.
Accessibility evaluations can also be used to advise design. If conducted as part of an iterative
design process, the results of an accessibility evaluation can be used to correct design deficiencies and
assist developers in selecting from a list of potential design alternatives. Both the checklist evaluation
and user testing play an important role in this type of evaluation.
Once the purpose of the evaluation has been determined, the evaluation goals should be
expressed as a desired outcome of the evaluation. Candidate evaluation goals might include the
following:
 Measuring conformance with applicable standards of Section 508
 Comparing the accessibility of product A to product B
 Selecting a design alternative from among two candidate alternatives by selecting the
alternative that maximizes accessibility to users without vision
 Determining the functional abilities required to operate the product
Proper evaluation goals formulated in terms of a desired outcome will assist in the selection of
accessibility evaluation techniques.
How do I perform a task analysis?
Task identification is the first, and most important, step in conducting a task analysis (Sanders
& McCormick, 1993; Drury, Paramore, Van Cott, Grey, & Corlett, 1988). The focus of the assessment
is the system comprised of the user and the device that the user is intended to operate. Task
identification is a structured analysis of all the user actions that are associated with the usage of a
particular device or class of devices (Drury, 1983). There are three potential sources of information
that the analyst may use to identify tasks. The first source is to observe users as they operate the
device (or a comparable device). Users perform tasks with a device because of the requirements of
their jobs - and thus it is beneficial to understand how users interact with devices as part of their
everyday routine. By observing how users interact with a device in realistic work environments,
researchers can decompose user actions into specific tasks.
The second source of information is technical documentation associated with the device, such
as user manuals and training materials. These documents may provide information on tasks that are
not readily observed, such as tasks performed only during initial setup of the device or in response to
some malfunction. These documents may also provide information on alternative methods of
performing tasks, beyond what current users may be observed doing. However, it should be noted that
most documentation is centered on the technology, not on the user. Researchers should use caution
when relying on technical documentation as the sole source of task analysis information. It is very
tempting to derive a list of product features from the technical documents rather than a list of user
tasks.
The third source of information about user tasks comes from the development of design
reference scenarios that describe how users are envisioned to use the device in various circumstances.
This source is particularly important when analyzing a new product or addition of new interfaces to an
existing product. In such cases, it is not possible to observe users interacting with the new device, and
21
technical documentation may still be immature. A design reference scenario is simply a narrative of
the key elements in the work environment, and the usage of the device in that environment. A typical
set of design reference scenarios would include perhaps 8-12 scenarios, each differing in the
circumstances or aspects of functionality that are used.
After completing the task identification, it is often useful to denote tasks that are associated
with maintenance, troubleshooting, or initial setup. Depending on the type of equipment and the
complexity of the device, maintenance, troubleshooting, and initial set-up tasks may be performed by
someone other than the end user, such as a technician or someone with specialized training.
Next, each task should be assigned a priority level. A prioritization of the task list should be
developed based on an estimate of the essential or core features of the device, versus advanced features
and features related to device set-up and maintenance (Fain & Folds, 2002). Priority may be divided
into three levels. Priority 1 tasks must be able to be successfully completed irrespective of impairment
in order for the product to be usable for all users. An inability to perform a priority 1 task because of
an impairment would likely severely limit the accessibility of the product under evaluation for users
with that impairment. Priority 2 tasks are secondary tasks that may be performed on an occasional
basis to access advanced functionality. The inability to perform a priority 2 task because of an
impairment, while not critical to the basic use of the product, may negate the value of advanced
features of the product. Priority 3 tasks are tertiary tasks that are not necessarily performed by all users
of the device, but must be performable by some operator on occasion. These tasks include initial setup
tasks that are not ordinarily repeated, major troubleshooting tasks, and major maintenance tasks that
users are expected to perform, albeit infrequently. The inability to perform a priority 3 task because of
an impairment would not affect the basic accessibility of the product unless the product is to be used
by a single user (or group of users all sharing the same impairment). Maintenance tasks may be
associated with any priority level. Some routine maintenance tasks that any user might perform, such
as loading paper, are judged to be priority level 1. Maintenance tasks that are performed rarely or only
by specially-trained users, however, are judged to be priority level 3.
The final step in the process is the development of task scenarios. The basic unit or component
of an accessibility test is a task scenario (or task sequence). Task scenarios are operationally realistic
arrangements of tasks. A series of scenarios (approximately 8-12) that exercises the tasks identified in
the task analysis should be developed. Repetition of key tasks is encouraged. The set of scenarios
should fully exercise the user interface components of the device. For simple devices, the set of
scenarios may include every single task identified during the task identification stage of the analysis.
For more complex devices, it is acceptable to formulate the scenarios so that a representative set of
tasks are selected from the full set of tasks.
When developing the scenarios, the evaluator should be mindful that every component of
interest on the device is covered. For example, the task scenarios should cover tasks that result in
common errors in addition to the more routine tasks. Some of the task conditions may have to be
simulated. For example, when evaluating a point of sale machine it is important to evaluate the task of
digitally signing for a transaction. An error involved with the signing task can be simulated and the
participant can be instructed to go through all of the steps involved in clearing the error without
actually having to induce the error.
22
How do I develop a Method of Test?
A Method of Test (MOT) document should be created to establish the plan for addressing the
test objectives. The MOT document serves as a coordination tool amongst evaluators and forces those
performing the evaluation to consider the details of the evaluation prior to data collection.
The first section of the MOT should identify the reason for performing the test, and the system
that is being tested. Evaluators should pay careful attention to documenting the configuration of the
device. Any additional software or other modifications above the baseline configuration of the device
should be clearly noted. In addition, each test objective should be described, and a summary of
planned test sessions should be outlined. The second section should describe, in considerable detail,
the methods that will be used in performing the test. Evaluation goals should be stated clearly. In
addition, the MOT should outline how the evaluation will produce an outcome that meets the stated
goals.
The number and type of participants that are required by the test should be described. For
example, a test objective that involves user-in-the-loop testing should describe the specific functional
limitations that are required to participate in the test. Care should be taken to choose participants that
represent 1) the user population that is expected to interact with the products and 2) the variety of
functional limitations that the test is designed to consider. For example, when studying users with low
vision, it is desirable to consider several different levels of general impairment as well as specific
impairments, such as central field degeneration, in order to evaluate a more complete range of
impairments. In addition to participant requirements, any specialized equipment required for the
evaluation, such as force meters or assistive technologies, should be specified. Additional resources,
such as personal attendants for participants or sign language interpreters for those without hearing,
should be documented.
A step-by-step documentation of the procedure should be included in the MOT. The procedure
section should document participant training, the particular tasks that the participant will perform, and
any debriefing activities performed as a part of the test. A detailed description of the data that will be
recorded should be provided. A performance measure can include task durations, error rates, task
completion frequencies, and subjective impressions. Methods of data reduction and analysis should
describe how the data will be interpreted. If any statistical analyses are planned, a description of each
analysis should be included. The criteria specifying how the evaluator will determine if a test
objective has been met should be included as well. For example, the test criteria might be that all of
the checklist evaluation items must receive a pass rating, at least sixty percent of the users must be able
to operate the device without experiencing difficulty, and no more than ten percent of participants
should experience extreme difficulty when operating the device.
Which evaluation techniques should I use?
The three main accessibility evaluation techniques are functional assessments, checklist
evaluations, and user testing. The accessibility evaluator will likely combine two or more of the
techniques described below to produce results that meet the goals of the evaluation.
Functional Assessment. The goal of a functional assessment is to determine the human
abilities needed to interact with the device. The functional assessment should be performed at the task
level. Required abilities should be identified for each task.
23
For example, selecting a menu item from the control panel of a machine requires vision in
order to identify the menu item label, reach in order to select the item, fine motor control in order to
select the button associated with the menu item, and strength to press the button. For the vision
requirement, the evaluator should identify the font size of the label and determine the position of the
operator during normal operation of the device. Based on these observations, the required level of
visual acuity can be calculated. The evaluator might determine that in order to complete the menu item
selection task, operators should have 20/70 or better visual acuity based on the size of the label and the
position of the operator. Similarly, the fine motor control ability can be assessed by measuring the
target and the positions of the surrounding controls. The activation of a small button with many
closely-arranged surrounding controls will require more fine motor control ability than a large button
with fewer surrounding controls. The evaluator might express fine motor control requirements in
terms of a user’s ability to select a 0.2 cm button from a grid of buttons arranged 0.5 cm apart.
Strength requirements can be measured directly. Using a calibrated force meter, the evaluator can take
direct measurements of the force required to activate the button associated with the menu item
selection. Reach requirements can also be assessed by direct measurement. Therefore, the evaluator
might say that the functional abilities required to perform a menu selection from the control panel are
20/70 or better vision, the ability to select 0.2 cm buttons from a grid of buttons spaced 0.5 cm apart, a
reach of 10 cm, and the ability to apply 0.2 lbs of force on a 0.2 cm button. Notice that the task did not
require hearing or the ability to speak.
The results of the assessment are used in determining the focus and scope of user testing. If the
device does not require hearing to operate, then there is no reason to test users that are deaf or users
with limited hearing. Also, if the evaluator identifies a number of instances where a particular ability
is exercised, it might be useful to focus user testing on the collection of data relative to that ability. For
example, if the functional ability testing identifies instances where reach requirements may exceed the
abilities of seated users, it might be useful to test a number of users in a variety of personal mobility
aids. However, if the functional ability for a given task clearly exceeds the capabilities of a given user
population, there is little reason to proceed with testing of associated tasks. For example, given that
the task of selecting a menu item from a control panel requires at least partial vision, there is little
reason to test a user without vision on that particular task.
An important exception to this general rule occurs when the goal of the evaluation is to provide
design feedback. The evaluator may want to know if the device would be accessible if obvious
accessibility problems are removed. In this instance, the evaluator would simply skip or assist the user
in the performance of task components that would otherwise be extremely difficult or impossible to
perform for a given user group. In the case of an evaluation involving a user who is blind, the
evaluator would assist the user by reading the menu label or perhaps directing the user to the position
of the associated control. By skipping only the task components associated with obvious accessibility
deficiencies, the evaluator can collect data about the remainder of the task components. A designer
could use the data to determine if additional accessibility interventions are required beyond the
correction of the obvious problems.
In addition, the results of the functional assessment can be used during the checklist evaluation
when the evaluation item is based on a human performance measurement. For example, when
24
designing for someone with limited strength, an important accessibility guideline is to not require the
user to apply more than five pounds of linear force to operate the equipment.
Finally, the functional assessment might be an important point of data in and of itself. By
collapsing the requirements of functional ability across all of the tasks, the evaluator can identify the
minimum set of abilities required to operate the device. This data might help consumers select
products that match their own abilities.
Checklist Evaluation. In order to perform a checklist evaluation, the evaluator must be skilled
in using measurement equipment such as calipers, torque meters, and force meters as well as the
general operation of the device to be evaluated. Also, the evaluator must be prepared to use sound
judgment and apply accepted principles when checklist items are ambiguous or ill-defined. In order to
complete the evaluation, the evaluator first selects the requirements, standards, and design guidelines
that both meet the evaluation goals and are applicable to the device. For example, if the primary
evaluation goal is to test conformance with Section 508, then the checklist evaluation should be
comprised of applicable Section 508 standards and related design guidance. If the goal of the
evaluation is to measure accessibility in general, then the evaluator should select a broad range of
recognized design guidelines, standards and principles. Potential checklist items can be derived from
the accessibility literature found in peer reviewed journal articles, standards found in government
regulations such as Section 508, and sound human factors design principles.
Once the list of checklist items is defined, the evaluator should define a method of evaluating
each checklist item. Methods of evaluation may include direct observation, measurement, or expert
inspection. Direct observation may be used when the checklist item evaluation method requires the
evaluator to inspect the device for a particular design element or characteristic. For example, a
checklist item derived from a guideline that recommends that the use of controls that required pinching
be avoided might instruct the evaluator to inspect the device for such controls. The evaluator may
determine that the device passes or fails the checklist criteria by simply inspecting the device to see if a
control that requires pinching is present. Other checklist items may require the use of a tool in order to
obtain some useful measurement. For example, a checklist item related to a guideline that
recommends that users not be required to apply more than 5.0 pounds of linear force might instruct the
evaluator to measure all linear control actions using a force meter. If any of the control action force
requirements exceed 5.0 pounds for proper operation, the evaluator should fail the checklist item.
Some checklist items rely on the expertise of the evaluator for proper determination of a pass/fail
rating. If the checklist item is ambiguous or ill-defined, the evaluator must make a reasonable
interpretation of the guideline based on prior experience and apply domain knowledge in order to make
a pass/fail judgment. If a checklist item derived from a guideline requiring sufficient contrast is
created, it is up to the evaluator to determine what sufficient contrast is. The adequacy of the contrast
will, in part, depend on the operating environment of the equipment and the size and coloration of the
user interface elements.
After the evaluation criteria have been defined for each checklist item, the evaluator performs
the evaluation by assigning a pass/fail rating to each checklist item. The evaluator should record all
measurements and keep a log of observations made during the evaluation. If the evaluation criteria
require the judgment of the evaluator, the evaluator should defend his or her judgment by documenting
25
the thought process used to arrive at the conclusion. After the evaluation is complete, a second
qualified evaluator should review the first evaluator’s findings.
User Testing. In some ways, user testing for accessibility is very similar to user testing for
usability. The evaluators should be properly trained in overall evaluation methodology, the specific
protocol for a given test, and the special concerns that arise when dealing with users with special
needs. The evaluator should be very well acquainted with the device under evaluation and should be
able to recognize and if possible rectify unusual problems that may arise, irrespective of whether the
problem is a consequence of a participant’s behavior. For example, if the device is a point of sale
machine, the evaluator should know how to handle signature pad errors, how to restore the system to
its proper configuration for the test, and whether the machine is malfunctioning in a way that will
render the test invalid.
The evaluation facility should be configured according to the requirements of the device and
the intended user population that will be participating in the evaluation. For example, if users are
expected to utilize assistive technologies during the course of the test, the device should be configured
to facilitate the use of specialized equipment. When testing software or hardware devices in an
integrated network environment, assistive technology software, such as screen readers or voice
recognition software, should be installed and configured prior to performing the test. In addition,
proper accommodations must be provided for participants with disabilities. These accommodations
include the physical space and any functional accommodations that are appropriate for the impairments
of the user. For example, access to the building and maneuvering space around the device should be
considered if the intended user population includes persons who use wheelchairs. If required, space
should also be provided for personal assistants or sign language interpreters.
In general, observers should not be present in the evaluation room while accessibility
evaluations are taking place, unless such observers are playing a direct role in the evaluation protocol
(e.g., watching for certain errors). Customer personnel and other interested parties may be
accommodated by allowing them to observe video feeds from the evaluation room. Video cameras
should be positioned so as to give a good view of the subject and a good view of the device during the
test. An audio recording should be made for the purpose of crosschecking key event reports. The
video recording should have a time of day counter, including seconds, that can be used to cross-check
task performance times.
Accessibility evaluations should be conducted using participants who are properly trained and
representative of the user population of interest. Although ease of access to users is always a
consideration, care should be taken to ensure that the “user population of interest” is not defined based
on the types of impairments that happen to be conveniently present. A typical accessibility evaluation
might include representatives from the following user populations:




Users with upper mobility limitations, including users with limited strength, limited
reach, and limited fine motor control
Users with lower mobility limitations, including users who use a manual wheelchair, a
powered wheelchair, and users who use personal mobility aids such as scooters
Users who are hard of hearing
Users who are deaf
26



Users who have visual limitations including users who are color blind, users with poor
visual acuity, and users with central field obstructions
Users who are blind
Users who have speech limitations
Users with cognitive limitations should also be tested, if possible. In general, it is best to test each
participant separately. Evaluation sessions should be scheduled so that the pace of the session is not
hurried, allowing participants to take breaks as desired.
Proper informed consent must be obtained before proceeding with any aspect of the test. The
participants’ rights to discontinue participation at any time should be respected. Care should be given
to ensure that each participant is fully capable of providing informed consent. Obtaining proper
informed consent is especially critical when working with users with certain cognitive impairments.
Evaluators should consult with a local research university’s Institute Review Board’s guidelines for
obtaining informed consent from users with disabilities.
Pilot testing of the test methods and evaluation instruments should be conducted before
proceeding with the evaluation. Internal pilot testing is often less formal than external pilot testing,
and is generally performed with participants recruited from within the organization performing the
testing. Documents, methods, and other materials should be updated as appropriate in accordance with
the pilot testing results. Internal pilot testing need not be performed with actual or simulated
impairments, although it is beneficial to do so when possible. External pilot testing should be
conducted with users who have some impairment of interest and are not part of the evaluation team.
Again, documents, methods, and other materials should be refined as appropriate in accordance with
the pilot testing results.
A test session should begin with participant orientation and training. The nature of the training
is largely determined by the extent to which the device’s learnability or intuitiveness is of interest. If
the device’s learnability or intuitiveness is not of interest, participants should be provided detailed
training on the use of the device. Most accessibility evaluations will fall into the second category. The
evaluator should point out each of the components that will be evaluated during the test session.
Training should also include instruction and practice on key event reporting. The evaluator should also
inform the participant about the purpose of the test and how the data collected during the test will be
used. If an assistant (e.g., a sign-language interpreter) accompanies the participant, the individual
giving the assistance should also be properly briefed about the procedures to be followed.
The evaluation should begin with the evaluator telling the participant about the scenario that is
going to be performed. For example, if the purpose of the test is to evaluate the keypad of a cellular
phone, the evaluator might explain to the participant that they will be retrieving a voice mail message
and then returning an urgent phone call. Once the background for the scenario has been described, the
evaluator should guide the participant through the scenario as required. There may be a tendency for
an evaluator to wish to assist the participant in the completion of a task. Care should be exercised to
ensure that any assistance offered by the evaluator does not unduly affect the outcome of the
evaluation.
27
At the beginning of a task, there is a clear “start” event - which can be generated by the
evaluator, by the participant, or by the device. The evaluator or an observer should use a stopwatch to
measure task performance time. The end of the task is similarly identified by a clear event, which can
be a device outcome, a participant-generated event, or an evaluator-generated event.
The evaluator should be particularly sensitive to the fact that a given device may not be very
usable for all users with disabilities, and that this could lead to some degree of frustration on the user’s
part. Evaluators should be prepared to intervene and move on to the next task to avoid unnecessary
frustration. In general, the test session should be conducted with the evaluator directing the participant
in the performance of the tasks.
The thinking-aloud approach to usability testing (Rubin, 1994; Dumas & Redish, 1993), while
popular, is not particularly well suited to accessibility evaluations because it may create unnatural task
performance demands that affect the validity of task performance measures (not to mention that
thinking-aloud data is of questionable validity). The thinking-aloud approach also makes it difficult to
collect data when testing individuals with speech impairments. As an alternative to continuous
thinking aloud, which emphasizes the stream of consciousness of the participant, the key-event
reporting method should be used. In this method, certain key events that are of interest to the
evaluation are identified in advance. The evaluator should brief the participant about the key events
and ask the subject to report them when they occur. Examples of key events that are often of interest
are as follows:
1.
2.
3.
4.
5.
6.
“I can’t find X”
“I can’t figure out how to do Y”
“I didn’t expect that to happen”
“I see that I have made an error” or “I didn’t mean to do that”
“I don’t know why that happened”
“I don’t know what to do next”
When the tasks associated with a given component of the device have been completed (or at
whatever time specified by the test procedure), a user rating of accessibility should be collected. The
rating should ordinarily be made using a Likert-type scale with an even number of rating points, unless
there is a clear need to have a neutral point in the scale. A four-point scale is preferred unless there is a
strong reason to use more scale points. Anchors are along the lines of:
1.
2.
3.
4.
= Completely unacceptable
= Marginally unacceptable
= Marginally acceptable
= Completely acceptable
The evaluator should record any pertinent observations that are made during the test session.
For example, if the participant makes a mistake that is obvious to the evaluator but is not part of a
participant comment, then the evaluator should make a note of the occurrence. The evaluator should
also make a note of any system malfunction or other event that might influence the interpretation of the
test results. For example, if the participant was inadvertently interrupted during the performance of the
test, then the evaluator should note the interruption. Important events that are not necessarily
28
verbalized should also be recorded. These events might include the beginning and end of task
sequences, the number and type of errors, or a record of tasks that are successfully completed.
The final activity in the test session should be a debriefing of the participant. The debriefing
should include opportunity for the subject to share any comments on the device and/or the test
methods. If possible and appropriate, the debriefing should include a quick review of the session,
including a summary of the subject’s performance (e.g., “You were able to complete 8 of the 10 tasks.
The two tasks you did not complete were scanning the large item and retrieving coins from the coin
dispenser.”). This review may help prompt the participant to make insightful comments. All serious
comments offered by the participant during this debrief should be fully documented. Ad hoc
comments made by the participant in earlier stages of the evaluation session, but not repeated by the
participant during the debriefing, should be documented if the evaluator judges them to be important
and germane to the accessibility of the product.
Data analysis involves the computation of task durations and the tabulations of user comments
and errors. Each error should be documented and categorized. A summary tabulation of errors by
error type should be generated. Analysis of data that involves interpretation of user comments should
be cross-checked between analysts.
How should I document the results of the evaluation?
The final step in the process is to integrate the results of the evaluation and document the
findings. Checklist items should be correlated with user test results when possible. For example,
when documenting a problem of the force required for spinning the bagging carousel, the evaluator
might organize the results as follows:
The force required to spin the bag carousel was 9.5 pounds, which exceeds the recommended
maximum force of 5.0 pounds. Seven out of eight users with upper mobility limitations could
not spin the carousel.
If the purpose of the evaluation is to provide design feedback, the results of the evaluation
should be organized by device component. The evaluator should precisely describe accessibility issues
for each disability type that are associated with each device component. For example, the evaluator
might offer the following feedback to designers:
The touchscreen is placed 56 inches above the floor, making it difficult for users in a seated
position to operate. Touchscreen buttons are not easily identifiable by touch, making it difficult
for visually impaired users to identify key control elements. Users with fine motor control
limitations will find the touchscreen difficult to use because of the size and spacing of the
buttons on the screen.
If the purpose of the evaluation is to document the general accessibility of the device, then the
results should be reported by disability type and task priority. For example, the evaluator might offer
the following observations:
29
Blind users, in general, found the device very difficult to use because no alternative to the
touchscreen was provided. Users without vision were able to complete 20% of the priority 1
tasks, 16% of the priority 2 tasks, and 10% of the priority 3 tasks.
Regardless of how the results are organized, key accessibility issues should be documented in
the conclusion of the evaluation report. It is important to clearly describe the accessibility issue and
the population that will likely be impacted by the issue. When possible, illustrations should be used to
communicate key points.
30
Accessibility Issues and Potential Solutions
Point of sale machines have potential accessibility issues in the following areas:
 Physical access
 Reach and visibility
 Labeling
 Displays
 Touchscreen interfaces
 Pointing devices
 Control panel buttons
 Control panel keypads
 Feedback
 Indicator lights
 Audio output
 Headphone jacks
 Barcode readers
 Scales
 Bagging area
 Bill acceptor
 Coin acceptor
 Card readers
 Signature area
 Output areas
 Writing and temporary storage areas
 Supplies area
 Trash slot
The following sections contain detailed information about common accessibility issues in each
of these areas. In addition, the populations impacted by the accessibility issues are discussed, and
potential solutions are proposed.
31
What are the common issues associated with physical access to the
machine?
Physical access to point of sale machines refers to the ability of users (particularly users in
wheelchairs) to position themselves in a location from which they can interact with the machine.
Physical access includes sufficient clear space in front of the machine and a clear path to the machine.
A clear path to the machine is not provided.
Detailed Description: Point of sale machines should be placed so that users with lower
mobility impairments have a path to and from the machine that is free from obstructions such
as narrow passages, steps or other changes in level, or excessively steep slopes.
Populations Impacted: Users with lower mobility impairments.
Potential Solutions: Provide a clear path to the machine that is at least 36” wide. A clear
path to the machine with a width of at least 36”, with a running slope no steeper than 1:20 and a
cross slope no steeper than 1:48 should be provided. The clear path should contain no changes
in level greater than ¼” that are not beveled (if the change in level is ½” or less) or ramped (if
the change in level is greater than ½”). For more details, see the ADA-ABA guidelines
referenced below.
Provide an appropriate floor or ground surface in the clear path to the machine. The floor or
ground surface should be stable, firm, and slip resistant. Carpet should be securely attached,
with a firm pad or no pad. The pile height of carpet should not exceed ½”. Openings in the
floor or ground surface should not allow passage of a sphere more than ½” in diameter, and
elongated openings should be placed so that the long dimension is perpendicular to the
dominant direction of travel.
Applicable Guidelines:
ADA-ABA – 302, 303, 403
32
Sufficient clear floor or ground space is not provided.
Detailed Description: If sufficient clear floor or ground space is not provided in front of a
point of sale machine, users in wheelchairs may have difficulty positioning themselves in a
location from which they can interact with the machine. In some situations, users may need to
turn around in order to depart from the machine after completing a transaction, and sufficient
space must also be provided to allow users in wheelchairs to turn around.
Populations Impacted: Users with lower mobility impairments.
Potential Solutions: Provide a minimum clear floor space of 30” by 48” in front of the device.
The minimum space required for a single stationary wheelchair and its occupant is 30” by 48”,
so a clear space of at least that size should be provided either parallel or perpendicular to the
machine. Ideally, a 48” by 48” clear space should be provided, to accommodate both forward
approach and parallel approach to the machine. The slope of the clear space should not exceed
1:48.
Figure 3: Minimum clear floor space for wheelchairs.
If applicable, provide sufficient clear space for a wheelchair to turn around in front of the
device. If a point of sale machine is installed in a location where users in wheelchairs will need
to turn around after using the machine (for example, a machine located against a wall, where
users would approach the machine from the front and then turn around and depart), a circular or
T-shaped turning space should be provided in front of the machine. A circular turning space
should be a minimum of 60” in diameter. A T-shaped turning space should be within a 60”
square minimum, with the arms and base 36” wide minimum as shown in the figure below.
33
Figure 4: Wheelchair turning space dimensions.
Provide an appropriate floor or ground surface in front of the device. The floor or ground
surface should be stable, firm, and slip resistant. Carpet should be securely attached, with a
firm pad or no pad. The pile height of carpet should not exceed ½”. Openings in the floor or
ground surface should not allow passage of a sphere more than ½” in diameter, and elongated
openings should be placed so that the long dimension is perpendicular to the dominant direction
of travel.
Applicable Guidelines:
ADA-ABA – 302, 304, 305
34
What are the common issues associated with reach and visibility?
Point of sale machines have a number of components, such as displays, keypads, and output
slots, that users must be able to see and/or physically interact with.
Some components of point of sale machines may be difficult for users with
mobility impairments to reach.
Detailed Description: Users of wheelchairs or other personal mobility devices may have
limited reach capabilities. Some users have power wheelchairs that allow them to raise and
lower their seats to increase their reach capabilities; however, many users have manual
wheelchairs that do not allow for these sorts of adjustments. Some wheelchair users are unable
to shift their upper bodies, limiting their access to only controls within arm’s length. Thus, it is
important that the components of a point of sale machine that users must interact with are
operable from a seated position, without requiring excessive leaning or reaching.
Figure 5: The touchscreen of a point of sale machine is too high, causing reach problems for a seated user.
Populations Impacted: Users with lower mobility impairments.
Potential Solutions: Follow the ergonomic standards to determine where to position the
controls to ensure easy access by all users.

The position of any operable control should be determined with respect to a vertical
plane that is 48 inches in length, centered on the operable control, and at the maximum
protrusion of the product within the 48 inch length.

Where any operable control is 10 inches or less behind the reference plane, the height
shall be 54 inches maximum (according to Section 508) or 48 inches maximum
(according to ADA-ABA) and 15 inches minimum above the floor. (See note below.)
35

Where any operable control is more than 10 inches and not more than 24 inches behind
the reference plane, the height shall be 46 inches maximum and 15 inches minimum
above the floor.

Operable controls shall not be more than 24 inches behind the reference plane.
Note that Section 508, which was based on older ADA guidelines, specifies a maximum height
of 54 inches. The newest ADA-ABA guidelines specify a maximum height of 48 inches, and a
forthcoming update to Section 508 is expected to follow suit.
Figure 6: The touchscreen of a point of sale machine is low enough for a seated user to reach it.
Allow adjustment of component positions. Where possible, allow users to adjust the position of
components to meet their specific needs. Components could be adjustable between two or
more discrete positions, or freely within a range of positions.
Applicable Guidelines:
ADA-ABA – 308.2.1, 308.2.2, 308.3.1, 308.3.2
Section 508 – 1194.25(j), 1194.31(f)
Section 255 – 1194.31(f)(2)(c)
ISO/IEC 71 – 8.3.1
36
Some components of point of sale machines may be difficult to see from a
seated position.
Detailed Description: Users who are seated in a wheelchair may be able to reach a component,
but may be unable to adequately see it. For example, a user might be able to press the keys on
a keypad, but may be unable to see the keys due to their orientation.
Populations Impacted: Users with lower mobility impairments.
Potential Solutions: Allow adjustment of component positions. Where possible, allow users to
adjust the position of components to meet their specific needs. Components could be
adjustable between two or more discrete positions, or freely within a range of positions. For
example, a display that can be tilted vertically can better accommodate both standing and
seated users.
Locate components so that all users can see them. When designing a point of sale machine,
consider the needs of both standing and seated users and attempt to place components in
locations and orientations that are visible for all users. For example, a display placed with the
screen perpendicular to the ground may be visible for both standing and seated users, although
the height of the display and the viewing envelope of the display must also be considered.
Applicable Guidelines:
ADA-ABA – 308.2.1, 308.2.2, 308.3.1, 308.3.2, 707.7.1
Section 508 – 1194.25(j)
HFDS – 5.11.1, 6.4.1.27
ISO/IEC 71 – 8.3.1
37
The required workflow forces users to change positions frequently.
Detailed Description: Some point of sale machine interactions require users to interact with a
number of different components of the machine. For example, in a typical self-checkout
transaction, a user must scan items, bag items, interact with the touchscreen to select options,
insert payment, retrieve the receipt and change, and retrieve purchases from the bagging area.
The user may have to change positions frequently during the transaction to access different
parts of the machine. Users with lower mobility impairments may have difficulty moving
around repeatedly during a transaction. Users who are blind may have difficulty maintaining
orientation to the machine if they must move from one area of the machine to another
repeatedly.
Populations Impacted: Users with lower mobility impairments; users who are blind.
Potential Solutions: Place components in close proximity, so that users do not have to change
positions as often. Where possible, group related components (such as the change dispenser
and the receipt printer) spatially so that users can interact with multiple components from a
single location.
Arrange components in a way that matches the required workflow. Consider the tasks that the
user must perform and the order in which they must be performed, and arrange the components
or groups of components to match that order. Design the system so that users only have to
change positions when moving from one task (for example, scanning items) to another (for
example, rendering payment and retrieving the receipt and change). Avoid designs that require
users to move back and forth within a single task.
Prompt the attendant to come to the user, rather than requiring the user to go to the attendant.
In systems where attendant intervention may be required, provide a prompt to the attendant to
come to the point of sale machine, rather than requiring the user to leave the machine to go to
the attendant.
Applicable Guidelines:
Section 508 – 1194.31(a), 1194.31(f)
HFDS – 6.4.1.12, 6.4.1.15, 6.4.1.16, 6.4.1.22
38
Some components are designed only for right-handed or left-handed use.
Detailed Description: Some components of point of sale machines may be designed to favor
the use of one hand (right or left) over the other. This can cause problems for some users with
upper mobility impairments, who may only have the use of one hand, and for some users with
lower mobility impairments, who may have difficulty positioning themselves so that the
appropriate hand is closest to the machine. Examples of components that may favor one hand
or the other include credit card slots and handheld barcode scanners.
Populations Impacted: Users with upper mobility impairments; users with lower mobility
impairments.
Potential Solution: Provide components that can be used with either hand. Components of
point of sale machines should be designed and located to be usable with either hand. For
example, on handheld barcode scanners, provide a grip that is not specifically molded for either
hand. For credit card readers, design the slot so that cards can be swiped equally well by either
hand in either direction.
Applicable Guidelines:
Section 508 – 1194.31(f)
HFDS – 6.4.1.6
39
What are the common issues associated with labeling?
Labels include text and graphics used to identify components of a point of sale machine, and
any instructional text located on the machine.
Small icons and text are difficult for users with low vision to perceive.
Detailed Description: Text and icons used in labels on point of sale machines may be difficult
for users with low vision to read if the characters or graphics are too small.
Figure 7: Very small labels and icons on a point of sale machine keypad.
Populations Impacted: Users with low vision.
Potential Solutions: Ensure that the font size of the text is sufficiently large. For 20/20 vision,
the Human Factors Design Standard (HFDS) recommends that the height of characters occupy
a visual angle of 16 to 24 minutes of arc. To compute the character height, use the following
formula
h = 2dTan(x/2)
where h is the character height, d is the viewing distance, and x is the desired angle in radians.
(One radian equals 3437.747 arc minutes, or 57.296 arc degrees.)
1194.31(b) of Section 508 states that a mode that does not require visual acuity greater than
20/70 must be provided. Multiplying the character height (h) calculated for 20/20 vision by 3.5
(70/20) yields the recommended character height for 20/70 vision for the specified viewing
distance.
While this font size may not be possible for all instances of text on a device, making the text as
large as possible will increase the chance that users with low vision will able to read the labels.
40
Figure 8: Large labels and icons on a point of sale machine keypad.
Ensure that icons are large enough for low vision users to see. The largest dimension (height
or width) of icons should be at least as large as the character height calculated above. Icons
should be made as large as possible, given the space available. Often, a control is fairly large,
but the icon on the control is only a small fraction of the total size of the control. If a control
will accommodate the same icon in a larger size, the larger size should be used to enhance
visibility for those with low vision.
Applicable Guidelines:
Section 508 – 1194.31(b)
Section 255 – 1193.43(b)
HFDS – 8.2.5.6.5, 8.2.5.6.6, 8.2.5.6.9
EITAAC – 5.2.1.2.1
41
Raised or recessed lettering may be difficult to perceive.
Detailed Description: Raised or recessed lettering is often the same color as the background,
so the contrast between the lettering and the background is insufficient. The lack of contrast
makes it difficult for users with low vision or low contrast sensitivity to distinguish the lettering
from the background surface.
Populations Impacted: Users with low vision.
Potential Solution: Ensure that raised or recessed lettering is different in color from the
control panel surface. The contrast between the lettering and the background surface should be
at least 3:1. If the device is to be used in very bright lighting or outdoors, then a contrast ratio
of at least 10:1 may be more appropriate. Using sufficiently contrasting colors will help users
with low vision or low contrast sensitivity perceive and read the lettering.
Applicable Guidelines:
Section 508 – 1194.31(b)
HFDS – 9.6.7
EITAAC – 5.2.1.2.1, 5.2.1.2.4
42
Labels are not clearly associated with the components that they label.
Detailed Description: Labels that are not clearly associated with the components that they
identify may cause problems for some users. Users may have difficulty locating components if
they are not clearly labeled, causing them to spend time searching for a particular component.
Users may erroneously associate a label with an incorrect component, causing them to commit
errors when interacting with the device. Users with low vision, who may have a limited field
of view, may have difficulty associating components and their labels if they are not associated
by proximity or some other type of coding technique.
Figure 9: Icons are not clearly associated with the buttons that they label.
Populations Impacted: Users with cognitive impairments; users with low vision.
Potential Solutions: Place labels in proximity to the components that they are labeling. If
possible, place labels directly on the component being labeled. If this is not possible, place
labels as close as possible to the component being labeled, and use spacing to ensure that the
label is unambiguously associated with the intended component and no others.
43
Figure 10: Icons are clearly associated (by proximity) with the buttons that they label.
Use grouping or other coding techniques to reinforce the association of labels to components.
Bounding boxes encompassing labels and components or lines connecting labels and
components may help to reinforce associations. The boxes or lines could be visual (printed on)
and/or tactile (raised), as appropriate. Other coding techniques, such as color coding or the use
of icons, may also be used. However, color coding should not be used as the sole means of
association, and coding techniques that rely on user vision are inaccessible to users who are
blind.
Applicable Guidelines:
Section 508 – 1194.31(b)
HFDS – 6.1.2.2.3, 6.1.2.2.6
44
Information presented in text labels is not accessible to users with visual
impairments.
Detailed Description: Information that is presented only as printed text is not accessible to
users who are blind, or to some users with low vision. Labels are used to identify controls and
components on point of sale machines, and some point of sale devices may provide labels that
contain instructions on how to use the device or a component of the device. It is important that
all users have access to all of the information that is necessary for the operation of the device.
Figure 11: No tactile labels are provided on a point of sale machine keypad.
Populations Impacted: Users who are blind; users with low vision.
Potential Solutions: Provide tactile labels for controls and components. Labels for controls
and components should be provided in a tactile format, which could include Braille, raised
lettering, or other raised markings that help identify controls.
45
Figure 12: Braille labeling on the “Enter” key on a point of sale machine keypad.
Provide critical instructions in Braille. Providing redundant labeling with at least the most
important instructions in Braille will increase accessibility of information for users with visual
impairments that are able to read Braille. (However, the percentage of users with visual
impairments that are able to read Braille is fairly low, so other methods of providing
information are also necessary.)
Provide information in an auditory format. The device should be capable of outputting
information in an auditory format (i.e., speech output). Auditory information should include
any necessary instructions on how to use the device, and may also include feedback, such as
repeating the names of controls when they are activated, to help users identify controls.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(a), 1194.31(b)
Section 255 – 1193.43(a)(2)
EITAAC – 5.2.1.1, 5.2.2.2
46
Icons used in place of text labels may be ambiguous.
Detailed Description: Graphical icons may be used to identify controls in place of text labels
for various reasons: to produce a device that is language-independent, to reduce the amount of
space required to label controls and components, or to achieve a desired aesthetic effect in the
design of the device. However, understanding icons, especially if the icons are very abstract
and/or are unfamiliar to the user, can be difficult, especially for users with cognitive
impairments.
Figure 13: Buttons on a point of sale machine are labeled only with ambiguous icons.
Populations Impacted: All users with vision, especially those with cognitive impairments.
Potential Solutions: Limit the use of icons. Consider the use of icons carefully, and avoid
using icons instead of text labels for the sake of aesthetics or other considerations to the
detriment of usability. Consider supplementing icons with text labels for clarity.
47
Figure 14: Buttons on a point of sale machine have text labels supplemented with icons.
Use standard or familiar icons. Icons representing certain functions or controls (such as stop,
play, fast forward, headphone output, volume, etc.) are widely used and are likely to be familiar
to most users. Avoid deviating too far from the common appearance of those types of icons.
Other icons (such as a depiction of a coin next to a coin slot) may be clear in the context in
which they appear. The use of new icons to represent abstract concepts should be avoided.
When new icons must be developed, test the icons with members of the user population to
ensure that the meaning of the icons is clear. User testing may provide insight into how to
design clearer, more meaningful icons. Care should be taken to sample a representative portion
of the targeted user population, including users with disabilities.
Applicable Guidelines:
HFDS – 8.13.3.1, 8.13.3.9, 8.13.3.10
EITAAC – 5.2.1.9.1, 5.2.1.10.1
48
Instructions may be difficult for users with cognitive impairments to
understand.
Detailed Description: Instructions that are poorly written, overly complex, or that are written
at too high a reading level may lead to comprehension problems for users with cognitive
impairments. Instructions describing a series of sequential actions may also be confusing, if the
instructions are poorly structured.
Figure 15: Unnecessarily complex instructions on the display of a point of sale machine.
Populations Impacted: Users with cognitive impairments.
Potential Solutions: Use simple language in instructions. Use the simplest language that
conveys the required information. Use familiar words, and use short sentences and paragraphs.
Use the imperative form of verbs (e.g., “Insert coins into the coin slot” instead of “Coins should
be inserted into the coin slot”). Use appropriate illustrations to reinforce the contents of the
text.
49
Figure 16: Simple instructions with an accompanying illustration on the display of a point of sale machine.
Ensure that instructions are grammatically correct and free from typographical errors.
Instructions should be reviewed by a technical writer or a proficient editor who is familiar with
the device for which the instructions were written.
Separate steps in a sequence into individual instructions. Break instructions into individual
steps that users can read and execute before proceeding to the next step. Present the steps in
the order in which they must be performed, and use bullets or numbering to distinguish
individual steps and reinforce the order of steps. White space should be used to separate steps.
Provide structure to the steps by grouping them into sub-goals. A long sequence of actions
may appear to lack structure, making it difficult for users to understand. Provide structure by
using headings to group sets of related steps. Use of indentation can help delineate sets of substeps.
Ensure that the sequence of actions is presented unambiguously and in the proper order,
especially if the instructions are presented via speech output. Instructions for actions should be
presented in the order in which they are to be executed (e.g., “Insert coins, then insert bills”
instead of “Before inserting bills, insert coins”).
Place CONDITION before ACTION. Goals or conditions for action should be presented before the
action, especially if the instructions are presented via speech output. For example, use the form
“To select the 3 PM showing, press 1” rather than “Press 1 to select the 3 PM showing.”
Test instructions with members of the user population to ensure that they are easy to
understand and to follow. User testing will help identify potential sources of errors or
confusion in instructions. Care should be taken to sample a representative portion of the
targeted user population, including users with disabilities.
50
Applicable Guidelines:
Section 255 – 1193.41(i)(2)(e), 1193.41(i)(2)(f)
HFDS – 2.6.3, 4.3.5.4.2, 4.3.5.4.3, 8.2.5.2.2, 15.5.1.1.1, 15.5.1.1.2, 15.6.2.3
EITAAC – 5.2.1.9.1, 5.2.1.10.1
ISO/IEC 71 – 8.7.2, 8.7.3, 8.7.4
51
What are the common issues associated with displays?
Most point of sale machines provide output (instructions, status information, error messages,
etc.) primarily through a visual display (often an LCD screen on newer machines). The display is
often a touchscreen, and doubles as the primary user interface with the device.
Glare makes it difficult for some users to see the display.
Detailed Description: Glare on display screens is a general usability issue for all users.
However, standing users can more easily shield the display with their bodies or adjust their
viewing angle to avoid glare, whereas users in wheelchairs may have more difficulty shielding
the display or adjusting their viewing angle. Also, because seated users may be looking up at a
display, glare from overhead lights may be more problematic.
Figure 17: The angle of the display results in glare for a seated user.
Populations Impacted: Users with lower mobility impairments.
Potential Solutions: Use an anti-glare display. Matte finish displays reduce glare by making
the surface of the display less reflective. Chemical coatings can also be used to reduce glare.
Provide an adjustable angle display. If the vertical tilt angle of the display is adjustable, users
can reposition the screen to reduce glare, instead of having to change their physical position
relative to the screen.
52
Figure 18: An adjustable display allows a seated user to adjust the display angle to reduce glare.
Use a hood to shield the display. A hood over the display can block direct light that causes
glare. However, a poorly designed hood might also block visibility for tall users.
Figure 19: A hood shields the display from overhead lights, reducing glare for seated users.
Position the device in an area where glare is not an issue. Sunlight and overhead lighting are
common sources of glare. If possible, position point of sale machines in areas where glare is
less likely, such as an area that does not receive direct sunlight. Alternatively, reduce overhead
lighting in the vicinity of the machine or direct it away from the display.
Applicable Guidelines:
Section 255 – 1193.41(b)(2)(a)
HFDS – 5.2.3
ISO/IEC 71 – 8.4.2, 8.4.4
53
LCD viewing angle limitations make it difficult to see the display from a seated
position.
Detailed Description: Many LCD screens are optimized for viewing from a particular angle,
and demonstrate a sharp drop-off in contrast and readability when viewed at angles that are offaxis. If the display of a point of sale machine is optimized for standing users, users who are
viewing the display from a wheelchair or other personal mobility device may have difficulty
seeing the contents of the display.
Populations Impacted: Users with lower mobility impairments.
Potential Solutions: Ensure that viewing envelope of the selected display accommodates both
standing and seated users. The viewing envelope of the display, which describes the range of
eye positions from which the contents of the display are visible, can be determined via simple
geometry based on the viewing angles of the display and the height and angle at which the
display is mounted. Ensure that the display’s viewing envelope includes the eye positions of
both seated and standing users.
Allow users to adjust the angle of the display. A vertical tilt adjustment for the display will
help to accommodate both seated and standing users.
Applicable Guidelines:
ADA-ABA – 707.7.1
HFDS – 5.1.2.6, 5.11.1
54
Parallax may be a problem for seated users.
Detailed Description: Certain display and control configurations (for example, an inset display
screen surrounded by soft keys) are susceptible to parallax errors. On-screen key labels are
designed to align with the location of bezel keys when viewed from a certain angle (e.g., when
standing in front of the display). When viewed from a different angle (e.g., when seated in
front of the display), the parallax error causes misalignment between the labels and the keys,
making it difficult to tell which label goes with each key.
Populations Impacted: Users with lower mobility impairments.
Potential Solutions: Place the display and the soft keys on the same plane. If the display and
the soft keys are coplanar, parallax errors are eliminated.
Provide an adjustable angle display. If the vertical tilt angle of the panel containing the
display and the soft keys is adjustable, users can reposition the screen to eliminate parallax
errors.
Provide guide lines from soft keys to the edge of the display to provide additional visual
association cues. Guide lines can visually “connect” soft keys to their on-screen labels,
allowing users to follow the guide lines to determine the appropriate key to press.
Applicable Guidelines:
ADA-ABA – 707.7.1
HFDS – 5.1.2.6, 9.4.2.6
55
Small text and icons are difficult for users with low vision to perceive.
Detailed Description: Text and icons on GUI displays may be difficult for some users to read
if they are too small.
Figure 20: Small text and icons are shown on the display of a point of sale machine.
Populations Impacted: Users with low vision.
Potential Solutions: Ensure that the font size used for text is sufficiently large. For 20/20
vision, the Human Factors Design Standard (HFDS) recommends that the height of characters
occupy a visual angle of 16 to 24 minutes of arc. To compute the character height, use the
following formula
h = 2dTan(x/2)
where h is the character height, d is the viewing distance, and x is the desired angle in radians.
(One radian equals 3437.747 arc minutes, or 57.296 arc degrees.)
1194.31(b) of Section 508 states that a mode that does not require visual acuity greater than
20/70 must be provided. Multiplying the character height (h) calculated for 20/20 vision by 3.5
(70/20) yields the recommended character height for 20/70 vision for the specified viewing
distance.
While this font size may not be possible for all on-screen text (including control labels, user
instructions, and other textual information), making the text as large as possible will increase
the chance that users with low vision will able to read the text.
56
Figure 21: Large text and icons are shown on the display of a point of sale machine.
Ensure that icons are large enough for low vision users to see. The largest dimension (height
or width) of icons should be at least as large as the character height calculated above. Icons
should be made as large as possible, given the space available.
Provide contrast adjustment for the display. Although users with low vision prefer and
generally require larger fonts, they may be able to read smaller fonts if the contrast is
sufficiently high. Provide a range of contrast settings for the user to adjust through a hardware
control. (Software controls are problematic, because if the contrast is insufficient for the user,
the user may not be able to read the display in order to find the contrast adjustment controls.)
Provide an alternate display mode with larger fonts and high contrast options. A userselectable alternate display mode that uses larger fonts and provides high contrast options, even
if it contains only the most important information and controls, will be useful for users with
low vision.
Provide alternatives to the visual display to facilitate interaction by users with low vision. A
voice display could be integrated into the device, so that visual content is presented in an
auditory fashion as well. For example, using a set of hardware controls, the user could navigate
through configuration menus that are voiced, without having to read the menus on the display.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(b)
Section 255 – 1193.43(b)
HFDS – 5.11.1, 5.11.7, 8.2.5.6.5, 8.2.5.6.6, 8.2.5.6.9, 8.18.3.1
EITAAC – 5.2.1.2.2
57
Complex or inconsistent user interface screens may be difficult for users to
understand.
Detailed Description: User interfaces that are complex (for example, displays that contain
many controls associated with multiple tasks) can be difficult for users with cognitive
impairments to navigate. Inconsistencies in displays, such as changes in control placement
from screen to screen or inconsistent use of terminology, can be confusing to users with
cognitive impairments. Similarly, inconsistent or excessive use of abbreviations can decrease
reading comprehension for users with cognitive impairments. Maintaining consistency and
keeping the interface as simple as possible are important usability considerations, and will
improve the accessibility of the device to all users.
Populations Impacted: Users with cognitive impairments.
Potential Solutions: Reduce the complexity of user interface screens where possible. Design
screens around individual user tasks (for example, a movie ticket point of sale machine might
have a screen dedicated to selecting a movie, and another screen dedicated to selecting a show
time). Avoid complex displays that contain a large number of options and controls.
Place common controls consistently throughout the user interface. If there are controls that
appear on multiple screens, such as navigation controls, ensure that the placement of those
controls is the same on every screen.
Use consistent terminology throughout the user interface. Ensure that names and abbreviations
are applied consistently throughout the user interface.
Limit the use of abbreviations. Abbreviations (especially those that may be unfamiliar to users)
should be used sparingly in the user interface.
Applicable Guidelines:
Section 255 – 1193.41(i)(2)(a)
HFDS – 2.3.1, 4.3.5.4.1, 8.2.5.4.4, 8.2.5.4.8, 8.2.11.1.2, 8.14.1.10
EITAAC – 5.2.1.9.1, 5.2.1.10.1
58
System time-outs may cause problems for some users.
Detailed Description: The user interface for point of sale machines may include system timeouts, which are situations where the user interface automatically changes states or resets if user
input is not received within a certain time period. People with disabilities often require more
time to respond than non-disabled users, so system time-outs can disrupt their transactions if
they are not notified that a time-out has occurred and allowed to request more time.
Populations Impacted: Users with cognitive impairments; users with upper mobility
impairments; users who are blind; users with low vision.
Potential Solution: Alert users when a time-out occurs, and allow them to request more time.
When a system time-out occurs while the user is performing a task, the user should be alerted
that the time-out has occurred, and given the option to request more time or cancel the task.
The user should be given sufficient time to respond to the alert before it expires. A good rule
of thumb for what constitutes sufficient time is 10 times the amount of time it would take an
average user respond.
Applicable Guidelines:
Section 508 – 1194.25(b)
Section 255 – 1193.41(g), 1193.41(i)(2)(f)
HFDS – 8.18.2.2
EITAAC – 5.2.1.7.1
59
What are the common issues associated with touchscreen interfaces?
Touchscreens are sometimes used as the primary user interface on point of sale machines. A
touchscreen interface allows the designer to accommodate a wide variety of controls and functions in a
relatively small area on the control panel, and allows users to interact directly with on-screen display
elements.
Touchscreen controls are not tactilely differentiable.
Detailed Description: Users without vision and some users with low vision navigate by touch,
moving their hands over the control panel to determine where various controls are located.
Touchscreens are inaccessible to users who navigate by touch, because controls displayed on
touchscreens are not tactilely discernable - they are merely graphical controls displayed on a
screen, and cannot be identified by touch.
Populations Impacted: Users who are blind; users with low vision.
Potential Solutions: Provide an alternate interface, such as a secondary control panel or a
voice display. Devices that use touchscreens, which are inaccessible to users without vision,
may be augmented with an alternative user interface. Touchscreen functionality could be
replicated in a fixed or attached auxiliary control panel using control elements with
functionality, position, and status that are easily discernible by touch. A voice display could be
integrated with the control panel, so that feedback is presented in an auditory fashion as well.
For example, using a numeric keypad as an input device, the user could navigate through
options that are voiced, without having to rely on vision to perceive the screen contents. The
voice display approach could be combined with voice recognition for hands-free device
operation.
Provide hardware controls for basic functions. If possible, provide redundant, tactilely
differentiable hardware controls for basic functions. This will allow users to perform those
basic functions without having to interact with the touchscreen. For example, an airport checkin machine might offer a hardware controls for increasing or decreasing the number of checked
bags, and a “print boarding pass” control; these controls would allow users to input necessary
data and complete a simple transaction without using the touchscreen.
Applicable Guidelines:
Section 508 – 1194.25(c), 1194.31(a)
Section 255 – 1193.41(a)(3)(e)
60
Touchscreen controls are easily activated and do not provide tactile feedback,
often resulting in unintentional control activations.
Detailed Description: Touchscreens require very little pressure to activate controls. The low
strength requirement is beneficial to users with limited upper body strength, but can cause
problems for other users, especially if controls on the touchscreen are small or closely spaced.
When controls are small or closely spaced, users who have upper mobility impairments or lack
fine motor control will have difficulty activating specific controls without also activating
adjacent controls. Users without vision may inadvertently activate touchscreen controls while
moving their hands over the control panel to locate hardware controls. Because no tactile
feedback is provided by touchscreen controls, if redundant visual and auditory feedback is not
provided when controls are activated, these accidental activations may go unnoticed.
Figure 22: Touchscreen numeric keypad buttons that are too small and too close together.
Populations Impacted: Users who are blind; users with upper mobility impairments.
Potential Solutions: Ensure that buttons are large and are spaced far enough apart to
minimize the possibility of accidental activation of adjacent buttons. When designing a
touchscreen interface, include adequate space between buttons. According to the Human
Factors Design Standard (HFDS), touchscreen buttons should be between 0.75” and 1.5” along
each side, with spacing between buttons of 0.13” to 0.25”. This will help ensure that a user
who does not have fine motor control is able to activate a button without accidentally activating
adjacent controls.
61
Figure 23: Touchscreen numeric keypad buttons that are larger and more widely spaced.
Provide an alternate display mode with larger, widely spaced controls. If the normal display
cannot be made accessible, providing an alternate display mode with larger, more widely
spaced controls, even if it contains only the most frequently used controls, will be useful for
users who lack fine motor control.
Provide alternatives to the touchscreen to facilitate interaction by users with disabilities.
Touchscreen functionality could be replicated in a fixed or attached auxiliary control panel
using control elements with functionality, position, and status that are easily discernible by
touch. A voice display could be integrated with the control panel, so that feedback is presented
in an auditory fashion as well. For example, using a numeric keypad as an input device, the
user could navigate through options that are voiced, without having to rely on vision to
perceive the screen contents. The voice display approach could be combined with voice
recognition for hands-free device operation.
Provide visual and auditory feedback when user input is received. Providing visual and
auditory feedback when user input is received can make up for the lack of tactile feedback, and
helps users detect unintentional activations. Visual feedback can be provided in the form of
salient visual changes in the display. Audible feedback might consist of simple tones, or
speech output when more descriptive feedback is needed.
Allow easy recovery from errors. A “Back” or “Undo” button should be provided to allow
users to recover from accidental inputs. Note that a button labeled “Cancel” is somewhat
ambiguous; a user may think that a “Cancel” button will cancel the entire transaction, rather
than cancel only the most recent input.
Applicable Guidelines:
Section 508 – 1194.25(c), 1194.31(a), 1194.31(f)
Section 255 – 1193.41(a)(3)(e), 1193.31(e)(2)(e)
HFDS – 9.4.2.4
Mercinelli – 2.5
62
A touchscreen placed for use by standing users may be difficult for users in
wheelchairs to reach.
Detailed Description: Users who are seated in wheelchairs or other personal mobility devices
may be unable to reach portions of a touchscreen if it is positioned for use by standing users.
This problem may be compounded if access to the machine by wheelchair is impeded by
objects around the machine. Some wheelchair users are unable to shift their upper bodies,
limiting their access to only controls within arm’s length. Thus, it is important that controls be
operable from a seated position, without requiring excessive leaning or reaching.
Figure 24: A user in a wheelchair having difficulty reaching the touchscreen.
Populations Impacted: Users with lower mobility impairments.
Potential Solutions: Follow the ergonomic standards to determine where to position the
touchscreen to ensure easy access by all users.

The position of any operable control should be determined with respect to a vertical
plane that is 48 inches in length, centered on the operable control, and at the maximum
protrusion of the product within the 48 inch length.

Where any operable control is 10 inches or less behind the reference plane, the height
shall be 54 inches maximum (according to Section 508) or 48 inches maximum
(according to ADA-ABA) and 15 inches minimum above the floor. (See note below.)

Where any operable control is more than 10 inches and not more than 24 inches behind
the reference plane, the height shall be 46 inches maximum and 15 inches minimum
above the floor.

Operable controls shall not be more than 24 inches behind the reference plane.
63
Note that Section 508, which was based on older ADA guidelines, specifies a maximum height
of 54 inches. The newest ADA-ABA guidelines specify a maximum height of 48 inches, and a
forthcoming update to Section 508 is expected to follow suit.
Allow adjustment of the position of the touchscreen. A touchscreen that can be adjusted
between two or more discrete positions, or freely within a range of positions, could
accommodate the needs of both seated and standing users.
Provide an alternate interface that is within reach for seated users. The alternate interface
could be a fully redundant interface to the touchscreen, or could consist of hardware controls
that provide a method for interacting with the screen without touching it, but still require the
user to look at the screen. In the latter case, care must still be taken to ensure that the
touchscreen is comfortably visible for seated users using the alternate interface.
Figure 25: An auxiliary control interface placed within reach of a user in a wheelchair.
Applicable Guidelines:
ADA-ABA – 308.2.1, 308.2.2, 308.3.1, 308.3.2, 707.7.1
Section 508 – 1194.25(j), 1194.31(f)
Section 255 – 1193.41(f)(2)(a), 1193.41(f)(2)(b), 1193.41(f)(2)(c)
ISO/IEC 71 – 8.3.1
64
What are the common issues associated with pointing devices?
Pointing devices are input devices that allow users to input spatial information using physical
motions and gestures. The inputs may be used to directly select on-screen controls, or to control a
free-moving cursor to make selections and perform more complex tasks such as highlighting and
dragging. Pointing devices that may be found on point of sale machines include mice, track balls,
touch pads, styluses, and others.
Users may have difficulty locating the pointing device.
Detailed Description: Because of the variety of different types of pointing devices, users with
visual impairments may be unsure where to search or what to search for when attempting to
locate the pointing device on a point of sale machine. Also, some types of pointing devices,
such as styluses, are movable and therefore may not be in the expected location.
Populations Impacted: Users who are blind; users with low vision.
Potential Solutions: Ensure that the pointing device is easy to distinguish from the rest of the
machine. The pointing device should be prominently located on the machine, in a location
where a user of the device would typically expect to find the pointing device. The pointing
device should be tactilely identifiable, and the visual appearance of the pointing device should
also contrast with the machine, to assist users with low vision to locate it.
If a stylus is provided, tether it to the device. Tethering the stylus to limit the range of motion
to what is required to use the stylus will reduce the likelihood of the stylus becoming lost. A
tether that retracts when the stylus is not in use would help keep the stylus in the desired
location, but the retraction force should not interfere with use of the stylus. Providing a
receptacle for users to place the stylus in after use could also help ensure that the stylus remains
in a convenient location.
Figure 26: A stylus that is tethered to the point of sale machine.
65
Applicable Guidelines:
Section 508 – 1194.31(a), 1194.31(b)
66
Using pointing devices can be difficult for users with upper mobility
impairments.
Detailed Description: Devices such as mice, track balls, touch pads, and styluses require users
to make small, controlled, and precise movements. Users who lack fine motor control may
have difficulty stabilizing their movements to provide accurate input with a pointing device.
As a result, they may have difficulty performing the desired actions, and may also activate
controls unintentionally.
Figure 27: On-screen controls are small and require precise movements to activate.
Populations Impacted: Users with upper mobility impairments.
Potential Solutions: Ensure that on-screen controls are large and are spaced far enough apart
to minimize accidental activation of adjacent controls. The active area of on-screen controls
should be large enough to provide a margin of error for successful user inputs. For example,
according to the Human Factors Design Standard (HFDS), touchscreen buttons should be
between 0.75” and 1.5” along each side, with spacing between buttons of 0.13” to 0.25”. This
will help ensure that a user who does not have fine motor control is able to activate a button
without accidentally activating adjacent controls.
67
Figure 28: On-screen controls are large, reducing the degree of precision required.
Ensure that the gain for free-moving cursor control is set appropriately. If the gain is too high,
small movements of the input device will result in large movements of the on-screen pointer,
which causes problems for users lacking fine motor control. A non-linear gain curve, which
results in very small cursor movements in response to small movements of the input device,
with the rate of movement increasing for larger movements of the input device, can
accommodate the needs of both users lacking fine motor control and users without motor
impairments.
Provide an alternate display mode with larger, more widely spaced controls. If the normal
display cannot be made accessible, providing an alternate display mode with larger, more
widely spaced controls, even if it contains only the most frequently used controls, will be useful
for users who lack fine motor control. If the user interacts with the display via a free-moving
cursor, lowering the gain when the alternate display mode is active may make it easier for users
to interact with the display.
Provide an alternative interface that does not require the use of a pointing device. For
example, a set of hardware controls that allows users to use arrow keys to move a highlight
cursor among the various on-screen controls, and provides a button for selection of the
highlighted item may be easier for users lacking fine motor control to interact with than a
pointing device.
Provide a clear area around the pointing device for users to brace their hands. For pointing
devices such as track balls and touch pads, providing clear space around the pointing device
where users can brace their hands to steady themselves and reduce tremors can help users
perform actions more accurately.
Provide visual and auditory feedback when user input is received. Providing visual and
auditory feedback when user input is received can make up for the lack of tactile feedback from
on-screen controls, and helps users detect unintentional activations. Visual feedback can be
68
provided in the form of salient visual changes in the display. Audible feedback might consist
of simple tones, or speech output when more descriptive feedback is needed.
Allow easy recovery from errors. A “Back” or “Undo” button should be provided to allow
users to recover from accidental inputs. Note that a button labeled “Cancel” is somewhat
ambiguous; a user may think that a “Cancel” button will cancel the entire transaction, rather
than cancel only the most recent input.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(f)
HFDS – 6.4.1.1, 6.4.1.9, 8.1.2.9, 8.15.11.1.13, 8.15.11.1.14
69
A free-moving cursor is inaccessible to some users with visual impairments.
Detailed Description: A free-moving cursor is an on-screen pointer that is typically controlled
by mouse, track ball, or similar devices. Users move the pointer over an on-screen control, and
click a button to activate the control. Because placement of the pointer typically relies on user
vision, users with visual impairments may be unable to interact with an interface in this way.
Populations Impacted: Users who are blind; users with low vision.
Potential Solution: Provide an alternative interface that does not require the use of a freemoving cursor. An example of this type of interface is a set of hardware controls that allows
users to use arrow keys to move a highlight cursor among the various on-screen controls and
provides a button for selection of the highlighted item, combined with voice output that
announces the name of the highlighted control.
Figure 29: An auxiliary control interface provides an alternative to a free-moving cursor.
Applicable Guidelines:
Section 508 – 1194.31(a), 1194.31(b)
Section 255 – 1193.41(a)(3)(f)
HFDS – 8.18.1.1, 9.6.1, 9.6.8
70
Some touchpads do not respond to materials other than skin.
Detailed Description: Some users with upper mobility impairments may use a pencil eraser,
mouth stick, prosthetic limb, or other device other than their fingers to interact with the
touchpad. However, some touchpads will not respond to touches from rubber or plastic
implements.
Figure 30: Attempting to interact with a touchpad with a pencil eraser.
Two types of touchpad technology are in use. The older type, which is rarely used anymore, is
the resistive touchpad. This type of touchpad consists of two membranes. When pressure is
applied to the outer membrane, it contacts the inner membrane and the position of contact is
detected. Because this type of touchpad relies on pressure to detect touch, the material with
which the pressure is applied is irrelevant. The newer type is the capacitive touchpad. This
type of touchpad detects touch based on electrical properties of the object that is touching the
pad. Certain types of objects (e.g., the tip of a pencil, gloved fingers, or even sweaty fingers)
do not produce detectable touches.
Populations Impacted: Users with upper mobility impairments.
Potential Solutions: Provide a touchpad that will respond to a variety of materials. If
possible, ensure that the touchpad will respond to touches from implements other than fingers.
Provide an interface that does not require the use of a touchpad. Provide an interface instead
of or in addition to the touchpad that will better accommodate users with upper mobility
impairments. For example, provide a set of hardware controls that allows users to use arrow
keys to move a highlight cursor among the various on-screen controls, and provides a button
for selection of the highlighted item.
71
Applicable Guidelines:
Section 508 – 1194.31(f)
Section 255 – 1193.51(c)
HFDS – 6.4.1.1
EITAAC – 5.2.1.14.1
72
Grasping a stylus may be difficult for some users.
Detailed Description: Styluses used with point of sale machines are often somewhat small and
thin, requiring a narrow grip. Users with upper mobility impairments that limit their dexterity
and fine motor control may have difficulty grasping and using such styluses.
Populations Impacted: Users with upper mobility impairments.
Potential Solutions: Provide a stylus that is the size of a standard pen or larger. Increasing
the length and diameter of the stylus to that of a standard pen or larger may make it easier for
some users to grasp and use the stylus.
Figure 31: The stylus is the size of a standard pen and has a rubbery grip.
Use a non-slip material for the stylus. The stylus should be covered in a rubbery, non-slip
material with a texture that facilitates grasping.
Applicable Guidelines:
Section 508 – 1194.31(f)
ISO/IEC 71 – 8.18.1
73
What are the common issues associated with control panel buttons?
Control panel buttons are mechanically operated push buttons that are used to interact with the
device.
Buttons mounted flush with the panel are difficult for users without vision or
with low vision to detect.
Detailed Description: Users with vision impairments may navigate by touch, by moving their
hands over the control panel in order to determine where controls are located. Buttons that are
mounted flush with the surface of the control panel are difficult for users without vision and
users with low vision to feel when they move their hands over the control panel. Furthermore,
users without vision typically depend on behaviors such as counting to find a specific control,
and this is problematic when there is insufficient tactile differentiation of the controls.
Figure 32: Buttons on a control panel are flush with the panel surface.
Populations Impacted: Users who are blind; users with low vision.
Potential Solutions: Ensure that buttons are sufficiently raised above the control panel so they
are tactilely discernable by users without vision. Buttons should be raised at least 1/32” above
the panel so that users can locate the buttons tactilely. This will improve the accessibility of the
buttons to users with visual impairments.
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Figure 33: Buttons on a control panel are raised above the panel surface.
Include Braille or raised large text on buttons that are flat to help users without vision
determine exactly what each button is. For devices where it is, for some reason, not possible to
sufficiently raise the buttons on the control panel, consider providing Braille labels on the
buttons so that users without vision will still have access to the buttons. Providing large, raised
lettering would have the additional benefit of assisting those with low vision in identifying the
functionality of the buttons.
Make the texture of the buttons different from that of the control panel to make the buttons
easier to distinguish tactilely. Providing a rougher texture on buttons if the control panel
surface is smooth or providing a more rubbery texture on the buttons if the control panel is
made of a hard material can help users without vision distinguish buttons from the control
panel surface more easily.
Combining all of these approaches (providing sufficiently raised buttons with accompanying
Braille labels or large raised lettering and a distinctive texture) would increase button
accessibility significantly.
Applicable Guidelines:
ADA-ABA – 707.6.1, 707.6.3.2
Section 508 – 1194.23(k)(1), 1194.25(c), 1194.31(a)
Section 255 – 1193.43(a)(2)(b), 1193.43(a)(2)(c)
HFDS – 6.4.1.7, 6.4.1.18, 6.4.1.19, 6.4.1.20, 6 4.1.23, 6.4.1.28, 9.6.10
75
Buttons that do not have sufficient contrast with the panel are difficult for users
with low vision to detect.
Detailed Description: If buttons are the same color as the control panel, they may blend in
with the panel, making it difficult for a user with low vision to distinguish the button from the
surrounding surface.
Figure 34: Buttons on a control panel have very little contrast with the control panel surface.
Populations Impacted: Users with low vision.
Potential Solution: Ensure that buttons are different in color from the control panel surface.
Buttons should be colored differently from the control panel, making them easy for a low
vision user to distinguish. Using sufficiently contrasting colors will aid users in distinguishing
buttons from one another. For example, a bright green “Enter” button would be easily
distinguishable from a dark gray control panel. Backlighting buttons may also help distinguish
them from the surrounding surface.
76
Figure 35: Buttons on a control panel have high contrast with the control panel surface.
Applicable Guidelines:
ADA-ABA – 707.6.3.1
HFDS – 6.1.1.4.12
77
Buttons are not identifiable as operable controls.
Detailed Description: Buttons that are designed to appear “sleek” or “modern” may not be
readily recognizable as operable controls. For example, users may interact with the device by
touching backlit areas of the control panel surface that use electrostatic touch detection, rather
than traditional mechanical controls. While these sorts of designs may be visually appealing,
users may have difficulty identifying the operable controls on the device – particularly users
with cognitive impairments, or users who are blind and rely on touch to perceive the presence
and location of controls.
Figure 36: A stylized button is not identifiable as an operable control.
Populations Impacted: Users who are blind; users with cognitive impairments.
Potential Solution: Ensure that buttons are readily identifiable as operable controls to all
users. Buttons should be easily identifiable as operable controls through their appearance,
tactile characteristics, and/or labels. Buttons should stand out from the control panel by virtue
of visual or physical characteristics so that users can identify them by sight or touch. Clear
labeling and instructions (“Press here”) may make it easier for users to identify non-traditional
types of buttons.
78
Figure 37: Design of the button and accompanying text help to identify the button as an operable control.
Applicable Guidelines:
ADA-ABA – 707.3, 707.6.1
Section 508 – 1194.23(k)(1), 1194.25(c), 1194.31(a)
Section 255 – 1193.41(a)(3)(b)
HFDS – 6.4.1.7, 6.4.1.18, 6.4.1.19, 6.4.1.20, 6 4.1.23
79
Buttons that are small and close together may be difficult to differentiate or
activate without activating adjacent controls.
Detailed Description: If control panel buttons are small and are placed too close together, they
may be difficult for users without fine motor control to activate without accidentally activating
adjacent controls. Small, tightly spaced control panel buttons are also more difficult for users
who are blind to differentiate by feel.
Figure 38: Buttons on a control panel are very small and close together.
Populations Impacted: Users with upper mobility impairments; users who are blind.
Potential Solution: Ensure that buttons are large and are spaced far enough apart to minimize
the possibility of accidental activation of adjacent buttons and to enhance tactile
differentiation. When designing the control panel for a point of sale machine, provide adequate
space between buttons. According to the Human Factors Design Standard (HFDS), minimum
spacing of 0.5” (with 2” preferred) is recommended for buttons that are not part of keyboards.
Make sure that the diameter of the buttons is large enough (up to a maximum diameter of 1”)
that a user who does not have fine motor control is able to activate a button even if he or she
does not hit the button directly in the center. Increasing button size and spacing will also aid
those who need to differentiate the buttons by feel. Buttons with very little separation can be
problematic for those who depend on the tactile quality of the buttons to find the ones they
need.
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Figure 39: Buttons on a control panel are larger and more widely spaced.
Applicable Guidelines:
Section 508 – 1194.23(k)(1), 1194.25(c), 1194.31(a), 1194.31(f)
Section 255 – 1193.41(e)(2)(a), 1193.41(e)(2)(b), 1193.41(e)(2)(c)
HFDS – 6.1.1.3.8, 6.1.5.8.1, 6.4.1.1, 6.4.1.3, 6.4.1.14, 9.6.10
ISO/IEC 71 – 8.12.3.2
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Buttons that are all shaped the same or that do not have shapes corresponding
to their functions are more difficult for the blind to memorize and for the
cognitively impaired to understand.
Detailed Description: Button shapes should correspond to their functionality. Commonly used
or important controls should be more prominent. Control panel buttons that are logically
grouped together, such as on a numeric keypad, should all have the same shape and
distinguishing features. Users who are blind rely on memorization to learn where specific keys
are located on a device. If all buttons are shaped exactly the same, memorizing the location of
the various buttons becomes a difficult task. For users with limited cognitive abilities, it may
be difficult to understand the difference between buttons that look exactly the same.
Figure 40: Buttons on a control panel are all shaped identically.
Populations Impacted: Users who are blind; users with cognitive impairments.
Potential Solution: Design buttons with distinguishing features, including differences in shape.
Ensure that buttons with different functions are distinguished from one another in some way.
For example, on many point of sale machines, the “Enter” button on the signature pad is larger
than all the other buttons because of its relative importance. It is also a good idea to associate
buttons that have related functions by making them all the same shape. In addition to shape
and size coding, color coding and grouping can be used as distinguishing features for controls.
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Figure 41: Buttons on a control panel are grouped and distinguished by size, shape, and color.
Applicable Guidelines:
ADA-ABA – 707.3, 707.6.1
Section 508 – 1194.23(k)(1), 1194.25(c), 1194.31(a)
Section 255 – 1193.41(a)(3)(b)
HFDS – 6.4.1.16, 6.4.1.18, 6.4.1.19, 6.4.1.22, 6.4.1.30
83
Buttons do not provide a surface that facilitates button activation.
Detailed Description: Buttons that are slick or have no concave curvature are more difficult
for some users to activate. Users without fine motor control or users that utilize manipulation
sticks may have difficulty activating buttons that are slick and not curved inward, because their
fingers or manipulation sticks may slip off the button and activate adjacent buttons.
Figure 42: Buttons on a control panel are slick and convex.
Populations Impacted: Users with upper mobility impairments.
Potential Solutions: The buttons on the device should be concave. Concave buttons help
prevent users’ fingers from slipping off the buttons.
Figure 43: Buttons on a control panel are concave and made from a high friction material.
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The buttons on the device should be made from a high friction material. A rubberized coating
or other high friction material helps prevent users’ fingers from accidentally slipping off the
controls.
Applicable Guidelines:
Section 508 – 1194.31(f)
Section 255 – 1193.41(e)(2)(g)
HFDS – 6.4.1.1, 6.4.1.7, 6.4.1.23
ISO/IEC 71 – 8.12.3.1
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Buttons requiring very little force to activate can increase the number of
accidental activations.
Detailed Description: Buttons that are activated with very light forces are more frequently
accidentally activated. This causes problems for users who are blind or who have low vision,
because they may rely on touch to locate buttons, and may accidentally activate buttons if the
activation force is too low. Users lacking fine motor control may touch buttons unintentionally,
and accidentally activate them if the activation force is too low.
Figure 44: Low activation force for a button results in inadvertent activations.
Populations Impacted: Users who are blind; users with low vision; users with upper mobility
impairments.
Potential Solution: Buttons should require a sufficient activation force to reduce the number
of accidental activations. Button activation forces in the range of 0.22 to 1.8 pounds are
recommended (Bullinger, Kern, and Muntzinger, 1988).
Applicable Guidelines:
Section 508 – 1194.31(a), 1194.31(f)
Section 255 – 1193.41(a)(3)(e), 1193.41(e)(2)(e)
Mercinelli – 2.4
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Buttons requiring high levels of force to activate can pose difficulties for users
with limited strength.
Detailed Description: Buttons that require a great deal of force for activation may be difficult
for users with limited strength to activate.
Populations Impacted: Users with upper mobility impairments.
Potential Solution: Buttons should require moderate levels of force to activate. ADA and
Section 508 guidelines place an upper limit of 5 pounds on control activation forces, but this
force is excessive for buttons, which are typically intended for fingertip operation. Button
activation forces in the range of 0.22 to 1.8 pounds are recommended (Bullinger, Kern, and
Muntzinger, 1988). However, button activation forces should not be too low, lest accidental
activations (e.g., when a user with tremors brushes against a control) become a possibility.
Applicable Guidelines:
ADA-ABA – 309.4
Section 508 – 1194.23(k)(2), 1194.25(c)
Section 255 – 1193.41(f)(2)(d)
HFDS – 6.1.5.8.1, 6.4.1.2, 6.4.1.11
Mercinelli – 2.4
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Chorded button operations can be difficult for users with upper mobility
impairments.
Detailed Description: Some control panel functions may require that two or more buttons be
pressed simultaneously. This can be difficult for users who cannot use both hands
simultaneously for various reasons, and for users who use manipulation sticks to activate
controls.
Populations Impacted: Users with upper mobility impairments.
Potential Solution: Avoid functions that require simultaneous button presses. If chorded
functions cannot be eliminated entirely, consider implementing a “sticky keys” function that
will allow the modifier key to be pressed before the action key, eliminating the requirement that
both keys be pressed at the same time.
Applicable Guidelines:
ADA-ABA – 309.4
Section 508 – 1194.23(k)(2), 1194.25(c), 1194.31(f)
Section 255 – 1193.41(e)(2)(d)
HFDS – 6.4.1.5, 6.4.1.6, 6.4.1.10, 8.18.2.1
EITAAC – 5.2.1.6.1
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Buttons do not provide sufficient tactile feedback.
Detailed Description: Tactile feedback indicating the activation of mechanical buttons is a
primary source of user feedback. If a button does not provide tactile feedback (in the form of a
mechanical click and/or perceptible displacement), users may be unsure whether or not they
successfully activated the control. This can lead to multiple activation errors (where users
press the button again because they were unsure if it was activated) and unintentional
activations (where users do not perceive that a button was pressed by accident).
Populations Impacted: Users who are blind; users who are deaf; users who are hard of
hearing; users with upper mobility impairments.
Potential Solution: Ensure that buttons provide adequate tactile feedback when activated.
Buttons should provide “snap action” feedback, with a gradual increase in resistance prior to
activation, followed by a sharp decrease in resistance after activation. Buttons with very low
travel distances should be avoided; buttons should travel between 1.3 and 6.4 mm when
activated. Providing visual and auditory feedback to supplement tactile feedback is also
recommended.
Applicable Guidelines:
Section 508 – 1194.31(a), 1194.31(b), 1194.31(c), 1194.31(f)
HFDS – 6.1.5.8.5, 6.4.1.31
Mercinelli – 2.4
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Some types of buttons do not respond to touch from materials other than skin.
Detailed Description: Certain types of controls, such as electrostatic buttons, do not respond to
touches from materials other than skin. Users with prosthetic limbs and users who use
manipulation sticks are therefore unable to activate these buttons.
Populations Impacted: Users with upper mobility impairments.
Potential Solution: Ensure that controls can be activated by materials other than skin.
Provide mechanically activated controls, or touch-sensitive controls that use a detection
technology that responds to a variety of materials other than skin. However, care must be taken
to ensure that the controls are not too sensitive, so that accidental activations become a
problem.
Applicable Guidelines:
Section 508 – 1194.31(f)
Section 255 – 1193.51(c)
HFDS – 6.4.1.1
EITAAC – 5.2.1.14
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What are the common issues associated with control panel keypads?
Control panel keypads include both numeric keypads and alphanumeric keyboards. In addition
to the issues listed for buttons, the following issues apply specifically to keypads.
Keypads may lack nibs on the “5”, “F”, and “J” keys.
Detailed Description: Users without vision are accustomed to having a small nib on the “5”
key on numeric keypads, and on the “F” and “J” keys on alphanumeric keyboards. These nibs
assist users to orient themselves to the positions of the various keys. Keypads and keyboards
that lack these nibs are difficult for users without vision to use, because they cannot orient
themselves to the correct keys and key positions.
Figure 45: The “5” key on the numeric keypad lacks a nib.
Populations Impacted: Users who are blind.
Potential Solution: Include sufficient nibs that can be easily felt on the “5”, “F”, and “J”
keys. On numeric keypads, always include a nib on the “5” key that can be easily differentiated
by feel. This can be a small raised dot or a dashed line. On alphanumeric keyboards, always
include nibs on the “F” and “J” keys so that users can orient themselves to the keyboard layout.
91
Figure 46: A nib is provided on the “5” key of the numeric keypad.
Applicable Guidelines:
ADA-ABA – 707.6.2
Section 508 – 1194.23(k)(1), 1194.25(c), 1194.31(a)
Section 255 – 1193.41(a)(3)(a)
HFDS – 6.4.1.18, 9.6.11
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Non-standard numeric keypads pose a problem for some users.
Detailed Description: There are two standard layouts for numeric keypads, the telephone
keypad layout and the adding machine layout (typical of most computer keyboards). Nonstandard numeric keypad layouts create difficulties for users who are blind, who rely on the use
of the standard layouts to orient themselves to the keypad, and for individuals with cognitive
impairments, who may become confused when faced with a non-standard layout.
Figure 47: A non-standard numeric keypad layout.
Populations Impacted: Users who are blind; users with cognitive impairments.
Potential Solution: Use a standard keypad layout on the control panel for the point of sale
machine. If a numeric keypad is used on the device, ensure that one of the standard layouts is
used. Also, ensure that the keys are tactilely discernable, and provide feedback to the user
when a key is pressed.
Figure 48: A standard numeric keypad layout.
93
Applicable Guidelines:
ADA-ABA – 707.6.2
Section 508 – 1194.23(k)(1), 1194.25(c), 1194.31(a)
HFDS – 6.4.1.18, 6.4.1.22, 6.4.1.30, 9.1.2, 9.1.3, 9.1.4, 9.1.5
EITAAC – 5.2.1.9.1, 5.2.1.10.1
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The common methods of cursor advancement for numeric keypad text entry
cause problems for some users.
Detailed Description: Some point of sale machines may require users to enter limited amounts
of text using the numeric keypad. Some numeric keypad text entry schemes automatically
advance the cursor to the next location after a time-out period, and others require the user to
manually advance the cursor. Some schemes adopt a semi-automatic approach, where the
cursor must be manually advanced to enter consecutive characters using the same number key,
but will automatically advance when a different number key is pressed. Each of these
approaches has advantages and disadvantages. Manually advancing the cursor requires the user
to make additional keystrokes, which may be difficult for users with upper mobility
impairments. The user may be required to move his or her hand off of the keypad to advance
the cursor, and to subsequently relocate and reorient to the keypad, which may be difficult for
users who are blind or who have low vision. Conversely, automatically advancing the cursor
may cause problems for users who are unable to press the keys fast enough to select the desired
letter before the timeout occurs; this may include users who are blind, users with low vision,
users with cognitive impairments, or users with upper mobility impairments.
Populations Impacted: Users who are blind; users with low vision; users with cognitive
impairments; users with upper mobility impairments.
Potential Solutions: Provide an accessibility mode that extends timeouts. If the automatic or
semi-automatic method is used, allowing users to set the timeout period to a duration
appropriate for their personal needs will alleviate timeout problems for those users.
Provide voice output when characters are entered and confirmed. Having the device voice the
current character as the user cycles through the available characters on a key would help users
with visual impairments select the desired character. Having the device voice each character as
it is confirmed (either manually or by a time-out), in a voice distinct from that used to voice the
selection of characters, would also help users know when a character has been confirmed and
know when the cursor has advanced to the next location.
Avoid numeric keypad text entry if possible. Because of the problems that numeric keypad text
entry can cause for users, consider an interface design that does not require direct text input, or
consider providing a full keyboard (a hardware keyboard or an accessible on-screen alternative)
if text input cannot be avoided.
Applicable Guidelines:
Section 508 – 1194.23(k)(3), 1194.25(b), 1194.25(c), 1194.31(a), 1194.31(f)
Section 255 – 1193.41(g)
HFDS – 9.1.1, 9.1.6, 9.1.16
95
What are the common issues associated with feedback?
A good interface must provide feedback to users. The user interprets feedback in order to
determine whether input was received, whether the desired action was executed, and whether the
desired consequences were achieved. Feedback is generally provided visually or audibly. Alerts and
error messages are special notifications that indicate to the user when certain actions must be taken.
An example of an alert is “Please show ID to cashier” when purchasing alcoholic beverages. An
example of an error message is “Invalid entry” when unexpected data is entered on a keypad.
The point of sale machine does not provide sufficient feedback to the user.
Detailed Description: Users with different disabilities have different needs for the amount and
type of feedback provided by a point of sale machine. The feedback that is provided may be
insufficient because it does not cover the full range of events for which feedback is required, or
it may be insufficient because it is provided in a form that is not useful to a user with a
particular disability (for example, visual feedback indicating that input has been accepted is not
useful to a user who is blind). Providing feedback for a wide range of events and user actions
in a variety of sensory modalities is beneficial for all users.
Populations Impacted: Users who are blind; users with low vision; users who are deaf; users
who are hard of hearing; users with upper mobility impairments.
Potential Solutions: Ensure that feedback is provided for all relevant events. Provide
feedback for all user inputs, system status changes, user or system errors, and other events that
are relevant to the user’s interaction with the machine. Feedback for different events should be
distinct from one another and appropriate to the events represented. For example, a simple
click may be sufficient to acknowledge a keypress, but a more prominent tone may be
necessary to indicate that an error has occurred.
Provide feedback in a visual format. Visual feedback is necessary for users with hearing
impairments, but it can also be helpful for users with low vision (if the feedback is sufficiently
large or if it also makes use of color or other visual cues), and for users with upper mobility
impairments (to help the user determine when unintentional inputs have been made).
Provide feedback in an auditory format. Auditory feedback is necessary for users who are
blind, and it can also be helpful for users with low vision and for users with upper mobility
impairments. Beeps and other sounds help users know that input was accepted (e.g., an item
was successfully scanned), and also serve to alert users if an unintentional input was made
(e.g., a quantity of “22” was entered instead of “2”). Voice output of more complex data (such
as the price of an item that was scanned, or indications of required user actions) helps users
with visual impairments verify transactions and allows them to operate point of sale machines
more effectively.
96
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(a), 1194.31(b), 1194.31(c), 1194.31(d)
Section 255 – 1193.43(a)(2)(a)
HFDS – 2.6.1, 5.11.1, 5.11.2, 8.15.8.3, 8.18.3.2, 8.18.4.1
97
System response time to user input is slow.
Detailed Description: Users rely on timely feedback from the system in response to their
inputs. If feedback is not provided in a timely fashion, users may conclude that their input was
not accepted and try again, leading to multiple activation errors. This is a usability problem for
all users, but it may exacerbate difficulties for users who are more prone to making input errors
(e.g., users who are blind or who lack fine motor control).
Populations Impacted: Users who are blind; users with low vision; users with upper mobility
impairments.
Potential Solutions: Minimize system response lag time. The system should provide timely
feedback to the user. The system should provide some response to user input within 500 ms. If
the system response to a user input takes longer than 500 ms, an interim “in progress”
indication should be displayed to acknowledge that the input was received and is being
processed.
Allow easy recovery from errors. A “Back” or “Undo” button should be provided to allow
users to recover from multiple activation errors or accidental inputs. Note that a button labeled
“Cancel” is somewhat ambiguous; a user may think that a “Cancel” button will cancel the
entire transaction, rather than cancel only the most recent input.
Figure 49: A confirmation screen with a “Back” button facilitates recovery from errors.
Applicable Guidelines:
Section 508 – 1194.25(b), 1194.31(f)
HFDS – 2.6.1, 6.3.1.5, 6.3.1.6, 8.8.2.24, 8.15.8.13, 8.15.11.1.13, 8.15.11.1.14
98
What are the common issues associated with indicator lights?
Indicator lights on point of sale machines are lights that illuminate to convey information (such
as system status) or to attract attention.
Information conveyed by indicator lights is not available to all users.
Detailed Description: Indicator lights depend on user vision to communicate information.
Therefore, the information conveyed by indicator lights is not accessible to some users with
visual impairments. Furthermore, the placement of indicator lights in certain locations on a
point of sale machine may make it difficult for users in wheelchairs to see the lights.
Additionally, indicator lights are not well suited to conveying complex information, and
attempting to convey complex information via indicator lights may cause confusion for users,
especially for users with cognitive impairments.
Figure 50: An indicator light is placed out of sight for a seated user.
Populations Impacted: Users who are blind; users with low vision; users with lower mobility
impairments; users with cognitive impairments.
Potential Solutions: Place indicator lights so that they are visible for both seated and standing
users. When placing indicator lights, consider the viewing angle of users who are accessing the
machine from wheelchairs, and avoid placing lights in locations that are only visible from a
standing position.
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Figure 51: An indicator light is placed so that a seated user can see it.
Provide a redundant alternative to vision that conveys the same information that is conveyed
visually. Providing audio output that communicates the same information that indicator lights
convey will increase accessibility for users who cannot see the indicator lights due to visual
impairments or due to the position from which they are using the machine. Simple audio
output such as beeps can be used to indicate status, but the sounds must be recognizable and
distinguishable to be effective. Voice output should be used to convey more detailed
information.
Avoid communicating complex information via indicator lights. Indicator lights are well suited
for conveying simple information that can be communicated by the presence or absence of a
light. Using indicator lights to convey more complex information (for example, by requiring
users to discriminate between flash rates or count a sequence of flashes) should be avoided.
Complex information should be presented by means of text, graphics, or voice output.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(a), 1194.31(b)
HFDS – 5.11.1, 5.1.2, 5.11.6, 5.11.8, 8.18.3.3
100
Color coding is sometimes used as the sole means of conveying information.
Detailed Description: Indicator lights that use only a change of color (especially when the
change is between red and green or between blue and yellow) as the only method of conveying
information may be difficult for color blind users and some users with low vision to discern.
For example, if a two-state light is used, with green representing the ready state and red
representing a fault state, a user with red/green colorblindness may not be able to determine if
the device is ready or is in a fault state.
Figure 52: A single light illuminates red or green to indicate status.
Populations Impacted: Users who are color blind; users with low vision.
Potential Solutions: Do not use color pairs that are easily confused by color blind users to
convey information. Red/green color blindness is most common; however, blue/yellow color
blindness occurs occasionally. Total color blindness, where users are not able to perceive color
and only see shades of grey, is extremely rare. Using color combinations other than red/green
and blue/yellow to represent information will help avoid confusion among most users who are
color blind.
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Figure 53: Separate red and green lights and redundant text indicate status.
Always provide a redundant alternative to color, such as text and/or location, that conveys the
same information that the color conveys. Anywhere color coding is used, the message
conveyed by that color coding should be conveyed through text as well, in order to ensure that
color blind users have access to the same information that other users do. For instance, in the
example used above, a text indication that says “Ready” when the copier is in the ready state
could be provided. The text message would communicate the same information to a color blind
user that the green light communicates to a non-color blind user.
Additional Comments: Although the solutions presented above will improve accessibility for
those who are color blind (and for some with low vision), they in no way solve the problem for
users who are blind and are therefore dependent on tactile or auditory differentiation of status
information.
Applicable Guidelines:
Section 508 – 1194.25(g), 1194.31(a)
Section 255 – 1193.41(c)
HFDS – 8.6.2.1.5, 8.6.2.5.2
EITAAC – 5.2.1.3.1, 5.2.1.3.2, 5.3.2.8
102
Flashing lights can trigger seizures in some users.
Detailed Description: Lights that flash at certain frequencies may induce seizures in users with
photosensitive epilepsy. Seizures are typically induced by flash rates between 2 Hz and 55 Hz,
and flashing that occupies a large portion of the visual field is more likely to induce seizures.
Populations Impacted: Users with photosensitive epilepsy.
Potential Solutions: Avoid flashing lights with flash rates between 2 Hz and 55 Hz. If flashing
indicator lights are used, ensure that the flash rate does not fall within these bounds.
Avoid flashing lights that occupy large areas. Flashing lights that occupy only part of the
user’s visual field are less likely to induce seizures than lights that fill the user’s visual field.
Therefore, flashing lights that cover large areas of the machine should be avoided.
Applicable Guidelines:
Section 508 – 1194.25(i)
Section 255 – 1193.43(f)
HFDS – 5.2.1.2
EITAAC – 5.2.1.12.1
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Overuse or misuse of indicator lights reduces their effectiveness.
Detailed Description: Indicator lights can be useful for communicating status to users or
attracting the attention of users. However, overuse of indicator lights (especially lights with
strong attention-getting qualities such as flashing or brightness) or misuse of indicator lights
can be an irritation or a distraction to users, and can cause the lights to lose their attentiondrawing power.
Figure 54: Overuse of indicator lights reduces their effectiveness for attracting attention or communicating
information.
Populations Impacted: All users with vision.
Potential Solutions: Avoid overuse of indicator lights, particularly for non-critical
information. “Overuse” of indicator lights is subjective, and the threshold will vary from
machine to machine. Generally, indicator lights should be used to communicate information
that is important to the user (for example, that user input is required or that an error has
occurred), and should not be used for decorative purposes, or to communicate information that
is obvious in other ways (for example, a power light is unnecessary if it is obvious from the
user interface that the machine is on).
The intensity of indicator lights should commensurate with their importance. The use of
intense indicator lights (larger, brighter, flashing) should be reserved for situations where it is
important to attract the user’s attention (for example, when action is required or an error has
occurred). More subtle (smaller, dimmer, non-flashing) indicator lights should be used for
more mundane purposes, such as acknowledging successful user input.
Ensure that the characteristics of indicator lights follow standard conventions. The Human
Factors Design Standard describes the following conventions:
 Red indicates error or malfunction conditions.
 Yellow indicates delays or situations where rechecking is necessary.
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



Green indicates satisfactory conditions, or that it is OK to proceed with an operation or
transaction.
Blue should be used as an advisory color.
White indicates a physical position or an action in progress.
A bottom-to-top or left-to-right movement in an array of indicator lights should
represent increasing values.
Applicable Guidelines:
HFDS – 6.2.2.1.27, 6.2.2.3.3, 6.3.3.5
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What are the common issues associated with audio output?
Many point of sale machines provide some form of audio output, ranging from simple beeps to
speech output. Audio output may be provided through speakers or through a headphone jack. Audio
output can be used to greatly improve the accessibility of a point of sale machine, particularly for users
with visual impairments.
Information is presented only in audio form.
Detailed Description: Users with hearing impairments may rely on visual displays to obtain
information from point of sale machines. If information is conveyed only via audio, some
users will be unable to perceive it.
Figure 55: Instructions are provided to the user only in audio form.
Populations Impacted: Users who are deaf; users who are hard of hearing.
Potential Solution: Provide redundant visual output for important audio output. All important
information that is conveyed via audio output should be accompanied by equivalent visual
information in the form of graphics, text, indicator lights, or other visual means.
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Figure 56: Instructions are provided to the user as audio and as text.
Applicable Guidelines:
Section 508 – 1194.31(c)
HFDS – 8.18.4.1
EITAAC – 5.2.1.4.2
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The volume level is insufficient.
Detailed Description: Some users may have difficulty hearing audio output at default volume
levels, particularly if the device is located in a noisy environment. Users with vision
impairments may rely exclusively on auditory information to use the device, so it is important
to ensure that the output volume can be adjusted to sufficient level.
Populations Impacted: Users who are hard of hearing; users who are blind; users with low
vision.
Potential Solution: Provide sufficient output volume and range of adjustment through the
built-in speakers and the headphone output. The range of volume available should be
implemented as described in Section 508 guideline 1194.25(f). Controls that allow users to
adjust the output volume within the range specified in 1194.25(f) should be provided.
Figure 57: A volume knob is provided to allow the user to adjust the output volume.
Applicable Guidelines:
Section 508 – 1194.25(f), 1194.31(a), 1194.31(b), 1194.31(c), 1194.31(d)
HFDS – 8.18.4.2
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Ambient sound from the environment interferes with the user’s ability to hear
audio output.
Detailed Description: Point of sale machines may be located in noisy environments, where
ambient sound from the environment makes it hard for users to hear audio output from the
machine. This may be particularly problematic for users who are hard of hearing, and for users
with vision impairments, who may rely exclusively on auditory information to use the device.
Populations Impacted: Users who are hard of hearing; users who are blind; users with low
vision.
Potential Solutions: Provide sufficient output volume and range of adjustment through the
built-in speakers and the headphone output. The range of volume available should be
implemented as described in Section 508 guideline 1194.25(f). Controls that allow users to
adjust the output volume within the range specified in 1194.25(f) should be provided.
Figure 58: A volume knob is provided to allow the user to adjust the output volume.
Provide a headphone jack. Providing a headphone jack allows users to attach their own
headphones for private listening to audio output. Headphones may also help users hear audio
output by partially blocking ambient noise.
Provide redundant visual output for important audio output. All important information that is
conveyed via audio output should be accompanied by equivalent visual information in the form
of graphics, text, indicator lights, or other visual means.
Applicable Guidelines:
Section 508 – 1194.25(e), 1194.25(f), 1194.31(a), 1194.31(b), 1194.31(c), 1194.31(d)
Section 255 – 1193.43(e)(2)(b)
HFDS – 8.18.4.1, 8.18.4.2
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Non-verbal audio output is not meaningful.
Detailed Description: Some point of sale machines use only simple non-verbal audio output
(i.e., beeps or tones) to communicate information to users. These tones may not be meaningful
in the absence of accompanying visual information, such as an on-screen message or graphic.
Users with visual impairments may not have access to visual information, and may therefore
have difficulty interpreting the meaning of non-verbal audio output. Users with cognitive
impairments may also have difficulty figuring out the meaning of non-verbal audio output.
Populations Impacted: Users who are blind; users with low vision; users with cognitive
impairments.
Potential Solutions: When possible, select sounds with characteristics that convey meaning. It
is difficult to convey meaning through simple sounds in a way that is universally understood,
but it may be possible in some situations. For example, a “positive” sound (a “ding” or a rising
tone) could be used to indicate that input has been accepted, and a “negative” sound (a “buzz”
or a descending tone) could be used to indicate that input has been rejected.
Consider using non-verbal sounds only to convey very simple information. For example, a
“click” sound could be used to indicate that a keypress has been accepted. The information is
conveyed by the presence or absence of the sound, and not by the characteristics of the sound.
When using sounds in this way, ensure that the sounds are temporally matched with the
associated event, so that the relationship between the event (for example, a keypress) and the
sound is clear.
Use verbal messages to convey information. When detailed information needs to be conveyed
via sound, use verbal information to explicitly and unambiguously convey the information.
This eliminates the requirement for users to interpret the meaning of the sound, and also serves
as a redundant means of providing the information, which benefits users with visual
impairments.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(a), 1194.31(b)
HFDS – 7.2.1.2, 7.2.1.4, 7.2.1.7, 7.2.1.8
110
Voice output is difficult to understand due to poor sound quality or interference.
Detailed Description: Voice output may be difficult for some users to understand because the
device’s speakers are not capable of reproducing the voice output clearly and without
distortion, particularly at higher volumes. Other sounds that accompany voice output, such as
background music, may also make it more difficult for users to understand the content of voice
messages.
Populations Impacted: Users who are blind; users with low vision; users who are hard of
hearing; users with cognitive impairments.
Potential Solutions: Ensure that the device’s speakers are capable of reproducing voice output
legibly through the full range of output volumes. The range of volume available should be
implemented as described in Section 508 guideline 1194.25(f). The speakers used in the device
should be tested to ensure that they are capable of reproducing voice output clearly and without
distortion through the entire range of volume adjustments.
Avoid background music or other sounds that may reduce the legibility of voice output.
Background music or other sound effects that are played back at the same time as voice output
messages may be distracting, and may reduce the legibility of the voice output.
Ensure that information conveyed by voice is accompanied by a redundant visual presentation.
Providing redundant visual information (for example, via on-screen text or graphics) may help
users who are hard of hearing obtain the information.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.25(f), 1194.31(a), 1194.31(b), 1194.31(c), 1194.31(d)
Section 255 – 1193.43(e)(2)(a), 1193.43(e)(2)(e)
HFDS – 7.3.2.1, 7.3.2.2, 8.18.4.1, 8.18.4.2
111
Voice output is not repeated.
Detailed Description: Users may fail to hear or understand voice output messages when they
are first presented. If the messages do not repeat, either automatically or under user control,
then users may be unsure how to proceed with their interactions with the device.
Populations Impacted: Users with cognitive impairments; users who are hard of hearing;
users who are blind; users with low vision.
Potential Solutions: Repeat voice messages automatically if the user does not respond within
some period of time. If the user fails to respond or take action within a reasonable amount of
time (a few seconds) after a voice message is presented, repeat the voice message.
Provide a control that allows the user to request that voice messages be repeated. This will
allow users to listen to messages again if they did not hear or understand the message initially.
Ideally, the repeat control should be a physical control (as opposed to an on-screen control) and
should be tactilely discernible to increase the accessibility of the control for users with visual
impairments.
Applicable Guidelines:
ADA-ABA – 707.5.1
Section 508 – 1194.25(e), 1194.31(a), 1194.31(b), 1194.31(c)
Section 255 – 1193.43(e)(2)(d)
HFDS – 8.18.4.2
112
Audio output via speakers may be inappropriate due to privacy concerns.
Detailed Description: Audio output may be required for some users to interact with point of
sale machines. The audio output may need to be at a relatively high volume to overcome
ambient noise or to accommodate users who are hard of hearing. However, some information
provided by point of sale machines, such as user account information or other private
information, should not be broadcast over speakers.
Figure 59: Potentially sensitive audio is output through speakers.
Populations Impacted: Users who are blind; users with low vision; users who are hard of
hearing.
Potential Solutions: Provide a headphone output. When headphones are connected, disable
the audio output through the speakers.
Figure 60: A headphone jack is provided for private listening.
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Avoid outputting potentially sensitive information through speakers. Consider whether any of
the information the point of sale machine might potentially output could cause privacy
concerns. If so, consider a design where private information is only output through the
headphone jack and not through the speakers, or consider giving the user the option of whether
or not private information should be output via the speakers.
Applicable Guidelines:
ADA-ABA – 707.4, 707.5
Section 508 – 1194.25(e), 1194.31(d)
Section 255 – 1193.43(e)(2)(e)
HFDS – 8.18.4.2
EITAAC – 5.2.1.11.1
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What are the common issues associated with headphone jacks?
A headphone jack on a point of sale machine allows users to connect a pair of personal
headphones to the device in order to hear audio output from the device more clearly and more
privately.
No headphone jack is provided on the device.
Detailed Description: Users with visual impairments often rely on audio output to interact
with point of sale machines. Interference from ambient noise may make it difficult for users to
perceive information provided via audio, especially for users who are hard of hearing. Use of
headphones allows users to hear audio output more clearly, and also enhances privacy.
However, some point of sale machines do not provide a headphone jack.
Populations Impacted: Users who are blind; users with low vision; users who are hard of
hearing.
Potential Solution: Provide a headphone jack so that users can connect personal headsets to
the device. The headphone jack should use a standard headphone connector (a 3.5 mm pin is
most common). External audio playback through speakers should be disabled when
headphones are connected.
Figure 61: A headphone jack is provided for private listening.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.25(e), 1194.31(a), 1194.31(b), 1194.31(c), 1194.31(d)
Section 255 – 1193.43(e)(2)(f)
HFDS – 8.18.4.2
EITAAC – 5.2.1.11.1
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Locating the headphone jack may be difficult for users with visual impairments.
Detailed Description: Headphone jacks are often used by users with visual impairments, who
may have difficulty locating the headphone jack if it is not prominently located and tactilely
discernible.
Figure 62: The headphone jack is located in an obscure location on the device.
Populations Impacted: Users who are blind; users with low vision.
Potential Solutions: Locate the headphone jack prominently on the device. Place the
headphone jack in a prominent location where users are likely to look or feel when searching
for the jack. Avoid placing the jack in an obscure location (too low or too high on the device,
on the side of the device, etc.).
Figure 63: The headphone jack is located in a prominent location on the device.
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Ensure that the headphone jack is tactilely discernible. The headphone jack should be
identified with a Braille label or other raised marking. The jack itself should be raised above
the surface of the machine (for example, surrounded by a raised ring). The jack should not be
obscured behind a cover.
Ensure that the headphone jack is visually discernible. The headphone jack should be located
in plain view on the device, and not hidden in an obscure location or behind a cover. Marking
the headphone jack with a distinctive, high contrast color will also help users with low vision
locate the jack.
Provide support for wireless headphone connectivity. The 3.5 mm connector (and to a lesser
extent the 2.5 mm connector) are still the most common methods for connecting headphones.
However, wireless technologies such as Bluetooth are becoming more prominent, and
providing support for wireless headphone connectivity would help to eliminate many of the
accessibility problems associated with headphone jacks.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(a), 1194.31(b)
HFDS – 6.4.1.15, 6.4.1.18, 6.4.1.22, 6.4.1.28
117
The headphone jack does not use a standard connector.
Detailed Description: 3.5 mm headphone connectors are the most common, and are used for
headphones for music devices. If the headphone jack does not support 3.5 mm headphone
plugs, many users will be unable to connect their headphones to the device.
Populations Impacted: Users who are blind; users with low vision; users who are hard of
hearing.
Potential Solution: Provide at least a standard 3.5 mm headphone jack. Support for other
connectors, such as 2.5 mm headphone connectors or wireless technologies such as Bluetooth
can also increase accessibility.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.25(e)
Section 255 – 1193.51(b)
118
Users may have difficulty inserting a plug into a headphone jack.
Detailed Description: Inserting a small headphone plug into a headphone jack can be difficult,
especially for users with visual impairments and users lacking fine motor control. The problem
may be exacerbated if the headphone jack is located in a cramped space or if it is covered.
Populations Impacted: Users who are blind; users with low vision; users with upper mobility
impairments.
Potential Solutions: Do not cover the headphone jack. Avoiding a cover on the headphone
jack eliminates the requirement for users to open the cover before plugging in headphones, and
also enhances visual and tactile discernability of the headphone jack.
If a cover is necessary, ensure that it does not interfere with use of the plug. Consider using a
cover that remains in the open position after the user opens it, so that the user does not have to
hold the cover open while plugging in headphones.
Avoid placing the jack too close to other controls, or in an area where access is obstructed.
Users lacking fine motor control may find it easier to insert a plug if they are able to brace their
hands while inserting the plug. Ensure that there are no obstructions around the headphone
jack (for example, avoid placing the jack in an interior corner where two or more panel surfaces
meet). Ensure that there are no controls near the headphone jack that may be accidentally
activated when a user braces his or her hand.
Design the jack to help guide the plug into the jack. For example, provide a concave area
around the headphone jack that helps to funnel the plug into the jack.
Applicable Guidelines:
ADA-ABA – 309.4
Section 508 – 1194.31(f)
HFDS – 6.4.1.1, 6.4.1.9, 6.4.1.12
119
The placement of the headphone jack allows the headphone cord to interfere
with use of the machine.
Detailed Description: Headphones are typically attached to point of sale machines by a cord.
The placement of the headphone jack could result in the headphone cord resting in an area
where it interferes with the use of the machine (for example, the cord may stretch across the
scanner area of a self-checkout machine). If users must change positions to interact with
different parts of the machine, headphone cords may restrict range of motion or become
unplugged during movement.
Figure 64: The headphone jack location allows the cord to interfere with use of the machine.
Populations Impacted: Users who are hard of hearing; users who are blind; users with low
vision; users with upper mobility impairments; users with lower mobility impairments.
Potential Solutions: Consider the expected workflow for the machine, and position the
headphone jack so that the headphone cord does not interfere with use of the machine. For
example, on a self-checkout machine, the headphone jack could be placed on the edge of
machine closest to the user, so that the cord does not stretch across the scanner and scale area.
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Figure 65: The headphone jack location prevents the cord from interfering with use of the machine.
Position the headphone jack in a location that allows sufficient range of motion to perform all
tasks. Consider the positions in which users, both seated and standing, will occupy when using
the device, and place the headphone jack in a location central to those positions. This will
allow users the necessary range of motion so they do not accidentally unplug their headphones.
Provide support for wireless headphone connectivity. Wired connectors are still the most
common methods for connecting headphones, but wireless technologies such as Bluetooth are
becoming more prominent. Providing support for wireless headphone connectivity would
eliminate interference from headphone cords.
Applicable Guidelines:
ADA-ABA – 308.2.1, 308.2.2, 308.3.1, 308.3.2
Section 508 – 1194.25(j)
HFDS – 6.4.1.12
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What are the common issues associated with barcode readers?
Some point of sale machines, such as self-checkout stations, contain barcode readers, which are
used to scan Universal Product Codes (UPCs). Barcode readers may be handheld, wall-mounted, or
integrated into a larger device.
Some users may have difficulty orienting a product properly for scanning.
Detailed Description: In order to scan barcodes, users must correctly orient the product to be
scanned so that its barcode is facing the reader. Because the placement of barcodes on product
packaging varies widely, locating the barcode and orienting the package so the barcode can be
scanned can be difficult for users with visual impairments. Users with upper mobility
impairments may also find it difficult to perform the fine manipulations required to orient
products and pass them over the reader repeatedly.
Figure 66: The barcode reader only scans one side of an item at a time.
Populations Impacted: Users who are blind; users with low vision; users with upper mobility
impairments.
Potential Solutions: Provide a reader that can read barcodes in multiple orientations with
high sensitivity. A reader that can scan barcodes in any orientation and that is sensitive enough
to successfully scan wrinkled or faded barcodes will be easier for users with visual impairments
to use, because it reduces the need for the user to accurately orient the barcode.
Provide a reader that can scan multiple product surfaces at once. A reader that can scan
multiple surfaces of a product (for example, the bottom and a side of the product) will be easier
for users with visual impairments to use, because it reduces the number of product orientations
the user must try before the barcode is read.
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Figure 67: The barcode reader only scans two sides of an item at a time.
Use a technology that can identify products based on proximity. Some technologies such as
RFID tags can be read by proximity, eliminating the need for the user to orient the product to
the sensor in a particular way. Use of RFID tags and readers to identify products would
simplify the process of scanning products at a point of sale machine.
Applicable Guidelines:
Section 508 – 1194.31(a), 1194.31(f)
HFDS – 6.4.1.1
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Large and/or heavy products can be difficult for some users to scan.
Detailed Description: If the barcode reader is wall-mounted or integrated into a console, then
users must position products near the scanner so the barcode can be read. Products that are
large and/or heavy may be difficult for some users to scan.
Figure 68: A large item is difficult to scan using an integrated barcode reader.
Populations Impacted: Users with upper mobility impairments; users with lower mobility
impairments.
Potential Solution: Provide a wireless handheld scanner. A handheld scanner allows users to
scan barcodes on large and/or heavy products without having to lift or reposition them. A
wireless scanner provides more flexibility by eliminating restrictions due to cord length.
Figure 69: A handheld barcode reader makes it easier to scan large items.
124
Applicable Guidelines:
Section 508 – 1194.31(f)
HFDS – 6.4.1.1
125
Grasping and operating a handheld barcode reader may be difficult for some
users.
Detailed Description: Some barcode readers may be difficult for users with upper mobility
impairments to grasp and use. The texture, weight, shape, and size of the reader can all
contribute to user difficulties. Furthermore, if the forces required to activate a barcode reader
are high, some users may have problems using the reader.
Figure 70: A handheld barcode reader without a handle is difficult to grasp.
Populations Impacted: Users with upper mobility impairments.
Potential Solutions: Ensure that the barcode reader is covered with a non-slip material. The
area of the reader that users grasp should be covered with a textured, non-slip (rubbery)
material that facilitates grasping. Avoid the use of slippery materials such as hard, glossy
plastic for areas that users grasp.
Provide a lightweight, well-balanced barcode reader. A barcode reader that is lightweight and
well-balanced (i.e., not excessively top-heavy) will be easier to use and less likely to be
dropped.
Provide a barcode reader with a “pistol grip” design. The “pistol grip” design provides a
better surface for grasping than a design without any sort of handle. The grip should be
moderately sized to facilitate use by a variety of hand sizes. The grip should not be excessively
contoured, and should be designed for use with either hand.
126
Figure 71: A handheld barcode reader with a handle is easier to grasp.
Ensure that the force required to operate the barcode reader is not excessive. If the user must
operate a trigger or other control to scan an item with the barcode reader, ensure that the force
required to activate the control does not exceed 5 pounds (22.2 N).
Applicable Guidelines:
ADA-ABA – 309.4
Section 508 – 1194.23(k)(2), 1194.25(c), 1194.31(f)
HFDS – 6.4.1.1, 6.4.1.2, 6.4.1.6, 6.4.1.11
ISO/IEC 71 – 8.18.1
127
Insufficient feedback is provided when a product is scanned.
Detailed Description: Feedback should be provided to all users when a product is scanned, so
that the user is informed that the product was successfully scanned. If feedback is provided in
only one modality (e.g., visually), then users with impairments in that modality will not
perceive the feedback. If feedback is insufficiently noticeable (e.g., a low-volume sound or
brief flash of light), users may fail to perceive it.
Figure 72: No feedback is provided when an item is scanned.
Populations Impacted: Users who are blind; users with low vision; users who are deaf; users
who are hard of hearing.
Potential Solution: Provide a clear indication, both visually and audibly, that a product has
been scanned successfully. Visual feedback can be provided in the form of an on-screen
message or by a light that illuminates on or near the scanner unit. Auditory feedback might
consist of a simple beep or a voice message that reports the name and/or price of the product
that was scanned.
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Figure 73: Visual and auditory feedback are provided when an item is scanned.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(a), 1194.31(b), 1194.31(c), 1194.31(d)
HFDS – 2.6.1, 5.11.2, 8.15.8.3, 8.18.3.2, 8.18.4.1
129
Audio output from nearby machines may cause confusion during scanning.
Detailed Description: It is common for several identical point of sale machines to be placed in
close proximity. If multiple machines are in use, users may mistake the auditory feedback from
a different machine for feedback from the machines they are using, potentially leading to
confusion and errors. This is particularly problematic for users with visual impairments, who
rely on audio feedback to understand what the machine is doing.
Populations Impacted: Users who are blind; users with low vision.
Potential Solutions: Provide product-specific auditory feedback to the user. Feedback in the
form of a verbal message announcing the name and/or price of the product that was scanned
will help users distinguish feedback from the machine they are using. This type of feedback
would also help users with visual impairments ensure that the proper item was scanned, and
that the proper price was identified. However, there may be privacy concerns associated with
announcing the specifics of some types of items. It may therefore be desirable to provide only
pricing and general item category information through a speaker, and provide specific item
names only through a headphone output.
Place the speaker so that output is directed toward the user. This should help reduce audio
crosstalk between machines. Placing the sound source in the area in which the user is working
(for example, between the display and the scanner) may also help the user identify the source of
sound and associate it with the machine he or she is using.
Figure 74: Directing audio output toward the user helps users identify the source of the audio.
Provide a headphone jack for personal listening. Allowing users to connect headphones has
several benefits. Headphones partially block outside sounds and provide audio directly into the
ears, which reduces interference from outside sound sources. Use of headphones also allows
more specific feedback to be provided to users by eliminating privacy concerns associated with
speaker output.
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Figure 75: A headphone jack is provided for private listening.
Provide unique feedback at adjacent devices. Consider providing audio output that can be
adjusted (for example, by adjusting the tone of beeps or the pitch of voice output over some
range). If multiple point of sale machines were placed in proximity to each other, each
machine could be set up to provide output that sounds slightly different from that of nearby
machines. This would provide a cue that would help a user distinguish the feedback from the
machine he or she is using.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.25(e), 1194.25(f), 1194.31(a), 1194.31(d)
Section 255 – 1193.43(e)(2)(e)
HFDS – 2.6.1, 8.18.4.2
131
What are the common issues associated with scales?
Some types of point of sale machines, such as those used in grocery stores and post offices,
make use of scales to weigh products or packages. Scales are typically integrated into the machine or
located on a counter adjacent to the machine.
Users may have difficulty locating the scale.
Detailed Description: Users with visual impairments may have difficulty locating scales that
are integrated into point of sale machines if sufficient tactile cues, labeling, and/or instructions
are not provided. The scale may not be distinguishable from another part of the machine (such
as the barcode scanning unit or a countertop surface, especially if the scale is the same color
and material as the surrounding area or if the scale’s surface is flush with the surrounding area
with no distinct edges to the weighing platform.
Figure 76: The scale is not tactilely discernible.
Populations Impacted: Users who are blind; users with low vision.
Potential Solutions: Provide visual and tactile cues to distinguish the scale. Using a different
material for the scale, providing a tactile cue such as a raised line around the edges of the scale,
or elevating the surface of the scale above the surrounding area by a small amount will help
users who rely on touch to locate the scale. Making the scale a different color from the
surrounding area or delineating the edges of the scale with a high contrast marking will help
users with low vision to locate the scale.
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Figure 77: Visual and tactile cues increase the discernability of the scale.
Provide visual and auditory instructions that inform users of the location of the scale. When
an item must be weighed, the display should indicate the location of the scale visually, for
example by showing an image of the device with the location of the scale highlighted. A light
that illuminates on or near the scale when an item is to be placed on the scale would also serve
as a visual cue to the location of the scale. Audio output of verbal instructions should also
indicate the location of the scale relative to a landmark familiar to the user (for example, “Place
the item on the scale, which is located to the left of the control panel.”).
Label the scale with tactile markings. Using Braille or raised lettering to label the scale will
assist some users with visual impairments.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.23(k)(1), 1194.25(c), 1194.31(a), 1194.31(b)
Section 255 – 1193.41(a)(3)(b), 1193.41(a)(3)(c)
HFDS – 6.4.1.18, 6.4.1.19, 6.4.1.28
133
Users may have difficulty knowing that the scale is ready for use.
Detailed Description: Some point of sale machines use scales that must be zeroized or
activated before an item can be weighed, requiring users to wait until prompted to place an item
on the scale. Insufficient feedback may be provided to indicate to users when it is appropriate
to place an item on the scale.
Populations Impacted: Users who are blind; users with low vision.
Potential Solution: Provide a clear visual and auditory prompt to direct users to place an item
on the scale. When the scale is ready for use, prompt the user visually via an on-screen
message or graphic and/or an indicator light that illuminates on or near the scale. Also prompt
the user auditorily with a meaningful verbal output (such as “place the item on the scale now”),
rather than with a tone for which the meaning may be unclear.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(a), 1194.31(b)
HFDS – 6.4.1.32, 8.18.3.2, 8.18.4.1
134
Users may have difficulty placing an item within the bounds of the scale.
Detailed Description: In order for items to be weighed properly, the items must rest fully
within the bounds of the scale’s weighing platform, without resting on any adjacent surfaces.
When a scale is integrated into a point of sale machine without clear delineation of the bounds
of the scale, it may be difficult for users with visual impairments to be certain that items have
been placed on the scale properly.
Figure 78: The bounds of the scale are not clearly defined with visual and tactile cues.
Populations Impacted: Users who are blind; users with low vision.
Potential Solutions: Provide visual and tactile cues to delineate the edges of the scale. Using
a different material for the scale, providing a tactile cue such as a raised line around the edges
of the scale, or elevating the surface of the scale above the surrounding area by a small amount
will help users who rely on touch to locate the edges of the scale. Making the scale a different
color from the surrounding area or delineating the edges of the scale with a high contrast
marking will help users with low vision to locate the edges of the scale.
135
Figure 79: The bounds of the scale are clearly defined with visual and tactile cues.
Provide visual and auditory feedback if an improperly placed item is detected. If the point of
sale machine detects that the item is improperly placed on the scale, notification should be
provided to the user both visually (for example, by an on-screen message or graphic) and
auditorily (for example, by verbal instructions describing the problem).
Applicable Guidelines:
Section 508 – 1194.31(a), 1194.31(b)
HFDS – 2.5.4, 6.4.1.32, 8.18.3.2, 8.18.4.1
136
The device does not provide sufficient feedback about the scale’s
measurement.
Detailed Description: Users need to have feedback about the weight of an item that is returned
by the scale so that they can verify the accuracy of the measurement. If the measured weight is
provided only visually, then users with vision impairments will be unable to obtain that
information.
Figure 80: Feedback about the scale’s measurement is not provided audibly.
Populations Impacted: Users who are blind; users with low vision.
Potential Solutions: The device should output the measured weight both visually and audibly.
The measured weight should be provided visually (via an on-screen message) and auditorily
(via voice output announcing the value). This also serves to prompt the user that it is OK to
remove the item from the scale.
137
Figure 81: Feedback about the scale’s measurement is provided audibly.
When possible, identify anomalous values and point them out to the user visually and audibly.
If a weight is measured that is outside the range of “normal” values that might be expected for a
given product (for example, because the product was not fully on the weighing platform, or
because additional items were resting on the weighing platform), provide feedback to the user
both visually and auditorily to indicate that there may be a problem. Users should have the
option to confirm that the measured value is correct, or to re-weigh the item.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(a), 1194.31(b)
HFDS – 2.5.4, 2.6.1, 8.15.8.3, 8.18.3.2, 8.18.4.1
138
What are the common issues associated with the bagging area?
Some point of sale machines, such as self-checkout stations, have an integrated bagging area
with racks that support bags into which items are placed after they are scanned. The bagging area
typically monitors the weight of items placed into bags to ensure that no unscanned items are placed in
the bagging area.
The bagging area is not designed to accommodate large or heavy items.
Detailed Description: In many self-checkout systems, users are required to place scanned
items into the bagging area, where the weight of items is monitored to ensure that only items
that have been scanned are bagged. However, this can lead to problems when large or heavy
items (such as a case of bottled water) must be placed in the bagging area. The bagging area
may not have room to accommodate bulky items, and the presence of heavy items may cause
errors with the bagging area scale.
Figure 82: The bagging area does not provide space to place large items.
Populations Impacted: Users with upper mobility impairments; users with lower mobility
impairments.
Potential Solutions: Provide a “skip bagging” option that permits users to avoid placing large
or heavy items in the bagging area. Allowing users to scan bulky items (perhaps with a
handheld barcode reader) without having to remove them from the shopping cart for bagging
simplifies the process for users with mobility impairments by reducing the need to move bulky
items from place to place. The “skip bagging” option could be provided automatically for
items that are known to be large or heavy, or it could be provided to the user as a selectable
option.
139
Figure 83: The device provides a “skip bagging” option.
Ensure that the bagging area can accommodate large or heavy items. If bulky items must be
placed into the bagging area, ensure that the bagging area is designed to accommodate them.
Ensure that there is clear space in the bagging area to accommodate common items that are too
large to bag (such as cases of beverages). Ensure that the bagging area scale is able to handle
heavy items without causing errors or delays for the user. Ensure that the bagging area is
relatively low (around knee height) to reduce the lifting distance required to transfer bulky
items to the bagging area.
Figure 84: The bagging area provides space to place large items.
Applicable Guidelines:
Section 508 – 1194.31(f)
140
The bagging area may generate confusing or spurious errors.
Detailed Description: In many self-checkout systems, users are required to place scanned
items into the bagging area, where the weight of items is monitored to ensure that only items
that have been scanned are bagged. However, user actions (forgetting to place items into the
bagging area, or placing extra items into the bagging area) or problems with monitoring the
bagging area (the scale does not register a very light item, or the scale is out of calibration) may
cause system errors that are confusing or false. Users with disabilities may have difficulty
recovering from such errors, because the errors are not communicated in a way that they can
perceive or understand.
Populations Impacted: Users with cognitive impairments; users who are blind; users with low
vision.
Potential Solutions: Design the system to reduce the number of spurious errors generated
from the bagging area. Minimize the number of “false alarm” errors generated by the system.
Ensure that scales remain calibrated and in good working order. Ensure that the bagging area
scale is designed to handle the range of expected item weights for the environment in which the
device is installed. (For example, in a grocery store, the scale must be able to detect something
as light as a spice packet, but must be able to handle something as heavy as a case of bottled
water.)
Provide clear feedback to users, both visually and audibly, to inform them of errors and to
describe the steps that must be taken to recover from them. When errors occur, the cause of the
error and the actions the user must take to resolve the error should be communicated via onscreen text and graphics and also via auditory verbal output. Users should also receive a
positive indication that the error has been resolved (for example, “scan your next item”).
Provide and remove error messages in a timely manner. Often, the software running on selfcheckout machines is slow or prone to lag, so that error messages are not generated as soon as
the condition causing the error occurs, or so that error message are not removed immediately
when the condition causing the error is resolved. Lag in providing and removing error
messages can cause confusion for users and may make recovery from error conditions more
difficult. (For example, a user may remove an item from the bagging area to resolve an error,
but if the message is not promptly removed, the user may remove additional items, possibly
exacerbating the problem.)
Applicable Guidelines:
Section 508 – 1194.31(a), 1194.31(b)
HFDS – 2.6.1, 7.1.1.3, 8.15.8.13, 8.15.11.1.4, 8.18.3.2, 8.18.4.1
141
Users are not sufficiently notified when items remain in the bagging area.
Detailed Description: When users collect their bags and depart from a self-checkout station,
they may accidentally leave items behind in the bagging area, perhaps because they cannot see
the items (due to visual impairments or a poor viewing angle into the bagging area from a
seated position) or because they forgot about some items that were purchased (due to a
cognitive impairment). Users (or attendants) should be notified if items remain in the bagging
area for some period of time after the conclusion of the transaction.
Populations Impacted: Users who are blind; users with low vision; users with cognitive
impairments; users with lower mobility impairments.
Potential Solution: Provide a visual and audible alert to the user that items remain in the
bagging area. The machine should remind users via an on-screen message as well as an
auditory alert that some items have not been removed from the bagging area. The alert should
be delayed long enough to not be a nuisance while the user is removing items, but should occur
quickly enough (perhaps a few seconds after the user last removed items from the bagging
area) that the user is notified before moving too far from the machine. If the machine is
attended, notifying the attendant may also be beneficial, so that the attendant can get the
customer’s attention and assist the customer with retrieving the items.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(a), 1194.31(b)
HFDS – 8.18.3.2, 8.18.4.1
142
What are the common issues associated with the bill acceptor?
Point of sale machines that accept cash for payment have a bill acceptor into which users insert
paper money. Bill acceptors typically require users to insert bills in a particular orientation.
Users may have difficulty locating the bill acceptor.
Detailed Description: The location of the bill acceptor often varies from machine to machine.
Therefore, users with visual impairment may be unsure of where to search for the bill acceptor.
Figure 85: The bill acceptor is difficult to discern visually and tactilely.
Populations Impacted: Users who are blind; users with low vision.
Potential Solutions: Ensure that the bill acceptor is easy to distinguish from the rest of the
machine. The bill acceptor should be prominently located on the machine, so that a searching
user can find it quickly, and it should be tactilely identifiable. The visual appearance of the bill
acceptor should also contrast with the machine, to assist users with low vision to locate it.
143
Figure 86: The bill acceptor is designed to be visually and tactilely discernible.
Provide tactile labels. The bill acceptor should be clearly labeled with a Braille label, raised
text, or other tactile markings.
Describe the location of the bill acceptor to the user both visually and auditorily. Provide both
on-screen text and/or graphics and auditory output indicating the location of the bill acceptor to
the user, making use of obvious landmarks on the machine to establish the location (i.e., “the
bill acceptor is located to the left of the display screen”).
Use an indicator light to draw attention to the bill acceptor. When ready to accept payment,
illuminate an indicator light on the bill acceptor to indicate its location and attract the attention
of the user.
Collocate all payment-related components. Group related components (in this case,
components related to rendering payment) together on the machine.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(a), 1194.31(b)
Section 255 – 1193.41(a)(2)(b), 1193.41(i)(2)(a)
HFDS – 6.4.1.16, 6.4.1.18, 6.4.1.22, 6.4.1.28, 6.4.1.30
144
Determining the proper orientation for inserting bills may be difficult for some
users.
Detailed Description: Most bill acceptors require users to insert bills in a specific orientation
(e.g., with the face of the bill up, and the top of the bill to the right). Determining the proper
orientation may be difficult for users with visual impairments (who may not be able to see
orientation instructions) and users with cognitive impairments (who may not be able to
understand orientation instructions).
Figure 87: No cues are provided on the bill acceptor to indicate the proper insertion orientation.
Populations Impacted: Users who are blind; users with low vision; users with cognitive
impairments.
Potential Solutions: Provide a clear graphic on the bill acceptor illustrating the proper bill
orientation. Provide a simple graphic located on or adjacent to the bill acceptor that shows the
proper bill orientation, using prominent, easily recognizable features of the bill (such as the
face on the bill) as landmarks.
145
Figure 88: A graphic on the bill acceptor shows the proper insertion orientation.
Provide a bill acceptor that accepts multiple bill orientations. If the bill acceptor can
successfully identify and accept bills in multiple orientations, the burden of orienting the bill
correctly is removed from the user, and the likelihood of a successful insertion increases.
Provide redundant, non-visual instructions describing the proper bill orientation. A voice
message describing the proper bill orientation (e.g., “insert bills with the face up”) will be
helpful to users with visual impairments.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(a), 1194.31(b)
HFDS – 8.18.3.2
EITAAC – 5.2.1.9.1, 5.2.1.10.1
146
Clear feedback on the inserted denomination and the outstanding balance is not
provided.
Detailed Description: Some point of sale machines do not provide accessible feedback to
users about the denomination of each bill that is inserted, or about the outstanding balance
remaining after each bill is inserted. Users may therefore be unsure that the proper bill was
inserted, or about how much additional payment must be inserted.
Populations Impacted: Users who are blind; users with low vision; users with cognitive
impairments.
Potential Solutions: Provide visual and auditory feedback about each bill that is inserted. As
each bill is recognized by the bill acceptor, display the denomination on screen and announce it
auditorily to help users ensure that the proper bill was inserted.
Provide updated information about the outstanding balance both visually and auditorily. After
each bill is inserted into the bill acceptor, update the outstanding balance and provide that
information to the user in both on-screen and auditory messages. If feedback about both the
bill that was inserted and the outstanding balance is provided, ensure that the two values are
easily distinguishable in both the visual and auditory output.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(a), 1194.31(b)
HFDS – 2.6.1, 8.15.8.3, 8.18.3.2
EITAAC – 5.2.1.9.1, 5.2.1.10.1
147
Clear feedback is not provided when a bill is rejected.
Detailed Description: Bill acceptors occasionally reject bills, usually because the bill was
inserted in an improper orientation or because the bill was too wrinkled or damaged. Often no
feedback other than the bill being ejected from the acceptor is provided.
Populations Impacted: Users who are blind; users with low vision; users with cognitive
impairments.
Potential Solution: Provide visual and auditory feedback that the bill was rejected. When a
bill is rejected, the device should notify the user both visually and auditorily that the bill was
rejected. Visual indications may include an on-screen message or an indicator light on the bill
acceptor itself. Auditory indications may include a recognizable tone or a verbal message. If
the reason for rejection is known (e.g., improper orientation), consider providing that
information to users to help them figure out how to resolve the problem.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(a), 1194.31(b)
HFDS – 2.6.1, 8.15.8.3, 8.18.3.2, 8.15.8.18
EITAAC – 5.2.1.9.1, 5.2.1.10.1
148
What are the common issues associated with the coin acceptor?
Point of sale machines that accept cash for payment often have a coin acceptor into which users
insert coins.
Users may have difficulty locating the coin acceptor.
Detailed Description: The location of the coin acceptor often varies from machine to machine.
Therefore, users with visual impairment may be unsure of where to search for the coin
acceptor.
Figure 89: The coin acceptor is difficult to discern visually and tactilely.
Populations Impacted: Users who are blind; users with low vision.
Potential Solutions: Ensure that the coin acceptor is easy to distinguish from the rest of the
machine. The coin acceptor should be prominently located on the machine, so that a searching
user can find it quickly, and it should be tactilely identifiable. The visual appearance of the
coin acceptor should also contrast with the machine, to assist users with low vision to locate it.
149
Figure 90: A label and a recessed area around the coin slot increase visual and tactile discernability.
Provide tactile labels. The coin acceptor should be clearly labeled with a Braille label, raised
text, or other tactile markings.
Describe the location of the coin acceptor to the user both visually and auditorily. Provide
both on-screen text and/or graphics and auditory output indicating the location of the coin
acceptor to the user, making use of obvious landmarks on the machine to establish the location
(i.e., “the coin acceptor is located to the left of the display screen”).
Use an indicator light to draw attention to the coin acceptor. When ready to accept payment,
illuminate an indicator light on the coin acceptor to indicate its location and attract the attention
of the user.
Collocate all payment-related components. Group related components (in this case,
components related to rendering payment) together on the machine.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(a), 1194.31(b)
Section 255 – 1193.41(a)(2)(b), 1193.41(i)(2)(a)
HFDS – 6.4.1.16, 6.4.1.18, 6.4.1.22, 6.4.1.28, 6.4.1.30
150
Users are required to insert coins before inserting bills.
Detailed Description: Some point of sale machines require users to insert coins before
inserting bills when rendering payment. From the user perspective, this represents an arbitrary
limitation, and it may cause difficulties for users with cognitive impairments.
Populations Impacted: Users with cognitive impairments.
Potential Solution: Allow users to insert coins and bills in any order. Removing the
restriction that coins be inserted before bills provides more flexibility for users to render
payment in whatever order is convenient to them.
Applicable Guidelines:
HFDS – 2.2.1
EITAAC – 5.2.1.9.1, 5.2.1.10.1
151
Inserting coins into a coin slot requires fine motor control.
Detailed Description: Coin acceptors on point of sale machines are often just a slot into which
coins are inserted. Inserting coins into a coin slot can be difficult for users that lack fine motor
control.
Populations Impacted: Users with upper mobility impairments.
Potential Solutions: Design the coin acceptor to reduce the amount of fine motor control
required to insert coins. Tapering the coin slot opening to guide coins into the slot or providing
a lip beneath the coin slot will help users insert coins more easily.
Provide a clear area around the coin acceptor for users to brace their hands. Providing a
space near the coin acceptor where users can brace their hands to steady themselves and reduce
tremors can help users perform actions more accurately.
Provide a coin “funnel” into which users can simply drop multiple coins. Providing a basket
or “funnel” into which users can drop multiple coins for the machine to count greatly reduces
the amount of dexterity required to insert coins for payment. If the types of transactions
conducted by the point of sale machine typically result in payment with coins, accepting coins
in this way would be particularly useful.
Figure 91: A funnel into which coins can be dropped makes it easier to insert coins.
Applicable Guidelines:
Section 508 – 1194.31(f)
Section 255 – 1193.41(e)(2)(h)
HFDS – 6.4.1.1, 6.4.1.9, 6.4.1.16
152
Clear feedback on the inserted denomination and the outstanding balance is not
provided.
Detailed Description: Some point of sale machines do not provide accessible feedback to
users about the denomination of each coin that is inserted, or about the outstanding balance
remaining after each coin is inserted. Users may therefore be unsure that the proper coin was
inserted, or about how much additional payment must be inserted.
Populations Impacted: Users who are blind; users with low vision; users with cognitive
impairments.
Potential Solution: Provide updated information about the outstanding balance both visually
and auditorily. After each coin is inserted into the coin acceptor, update the outstanding
balance and provide that information to the user in both on-screen and auditory messages. The
on-screen information should be updated immediately; consider providing the updated balance
auditorily only if there has been a lull of a few seconds between coin insertions, to avoid
confusing audio output when coins are inserted in rapid succession.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(a), 1194.31(b)
HFDS – 2.6.1, 8.15.8.3, 8.18.3.2
EITAAC – 5.2.1.9.1, 5.2.1.10.1
153
Clear feedback is not provided when a coin is rejected.
Detailed Description: Coin acceptors occasionally reject coins. Coins may be rejected
because they are not accepted by the machine (for example, some machines do not accept
pennies for payment), because they are not recognized by the machine (for example, foreign
coins), or for other reasons. Often no feedback other than the sound of coins falling into the
coin output is provided.
Populations Impacted: Users who are blind; users with low vision; users who are deaf; users
who are hard of hearing; users with cognitive impairments.
Potential Solution: Provide visual and auditory feedback that the coin was rejected. When a
coin is rejected, the device should notify the user both visually and auditorily that the coin was
rejected. Visual indications may include visibility of rejected coins, an indicator light on the
coin acceptor itself, or an on-screen message. Auditory indications may include a recognizable
tone or a verbal message. If the reason for rejection is known (e.g., the coin is a denomination
that is not accepted by the machine), consider providing that information to users to help them
figure out how to resolve the problem.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(a), 1194.31(b), 1194.31(c)
HFDS – 2.6.1, 8.15.8.3, 8.18.3.2, 8.15.8.18
154
What are the common issues associated with card readers?
Most point of sale machines have an associated card reader that is used to read data from credit
cards, debit cards, or other types of cards for payment or identification. Some point of sale machines
may also provide slots for users to insert memory cards. The card reader may be integrated into the
point of sale machine, with only a slot for swiping or inserting cards visible to the user, or it may be a
separate device with its own controls and user interface that interacts with the point of sale machine.
Users may have difficulty locating the card reader.
Detailed Description: The location and type of card reader often varies from machine to
machine. Therefore, users with visual impairments may be unsure of where to search for a card
reader, or what type of card reader to search for.
Figure 92: The card reader is unlabelled and has poor visual contrast.
Populations Impacted: Users who are blind; users with low vision.
Potential Solutions: Ensure that the card reader is easy to distinguish from the rest of the
machine. The card reader should be prominently located on the machine, so that a searching
user can find it quickly. It should also be tactilely identifiable as a card reader. For example,
instead of providing only a small slot in the machine into which a card must be inserted,
provide an interface that can be easily located and identified by touch. The visual appearance
of the card reader should also contrast with the machine, to assist users with low vision to
locate it.
155
Figure 93: The card reader is labeled and has good visual contrast.
Provide tactile labels. The card reader should be clearly labeled with a Braille label, raised
text, or other tactile markings.
Describe the location of the card reader to the user both visually and auditorily. Provide both
on-screen text and/or graphics and auditory output indicating the location of the card reader to
the user, making use of obvious landmarks on the machine to establish the location (i.e., “the
card reader is located to the left of the display screen”).
Use an indicator light to draw attention to the card reader. When a card must be read (for
example, when the machine is ready to accept payment), illuminate an indicator light on the
card reader to indicate its location and attract the attention of the user.
Collocate all payment-related components. Group related components (in this case,
components related to rendering payment) together on the machine.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(a), 1194.31(b)
Section 255 – 1193.41(a)(2)(b), 1193.41(i)(2)(a)
HFDS – 6.4.1.16, 6.4.1.18, 6.4.1.22, 6.4.1.28, 6.4.1.30
156
Determining the proper orientation for inserting or swiping a card may be
difficult.
Detailed Description: Most card readers require users to insert or swipe cards in a specific
orientation (e.g., face-up, or with the magnetic stripe up and to the left). Determining the
proper orientation may be difficult for users with visual impairments (who may not be able to
see orientation instructions) and users with cognitive impairments (who may not be able to
understand orientation instructions).
Figure 94: The proper orientation for swiping a card is not shown.
Populations Impacted: Users who are blind; users with low vision; users with cognitive
impairments.
Potential Solutions: Provide a clear graphic on the card reader illustrating the proper card
orientation. Provide a simple graphic located adjacent to the card reader that shows the proper
card illustration, using only one or two prominent features of the card (such as the magnetic
stripe, the name on the card, or the alignment arrow on a memory card) as landmarks. If
possible, avoid perspective drawings that may require users to perform mental geometry to
work out the proper card orientation.
157
Figure 95: A label shows the proper orientation for swiping a card.
Provide a card reader that accepts multiple card orientations. If a card reader can successfully
read a card in more than one orientation (for example, stripe up and stripe down), the likelihood
of a successful insertion increases.
Provide redundant, non-visual instructions describing the proper card orientation. A voice
message describing the proper card orientation (e.g., “insert card with the magnetic stripe
facing down and to the left”) will be helpful to users with visual impairments.
Provide support for contactless card reading. Contactless cards (which use barcodes or RFID
technology to store data) eliminate the need for the user to determine the proper card
orientation.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(a), 1194.31(b)
HFDS – 8.18.3.2
EITAAC – 5.2.1.9.1, 5.2.1.10.1
158
Users lacking fine motor control may have difficultly aligning and inserting a
card.
Detailed Description: Precisely aligning a card with a card reader slot for insertion or swiping
can be difficult for users lacking fine motor control.
Figure 96: The card slot is not designed to guide the card into the slot.
Populations Impacted: Users with upper mobility impairments.
Potential Solutions: Design the card slot so that it guides the card into the slot. A slot design
with an opening that tapers into the insertion slot or a design that provides a clear area for the
user to rest the card before sliding or inserting it reduces the amount of fine motor control
required to interact with a card reader.
Figure 97: The card slot is designed to help guide the card into the slot.
159
Provide a clear area around the card slot for users to brace their hands. Providing a space
near the card slot where users can brace their hands to steady themselves and reduce tremors
can help users perform actions more accurately.
Provide support for contactless card reading. Contactless cards (which use barcodes or RFID
technology to store data) eliminate the need for the user to align and insert the card.
Applicable Guidelines:
Section 508 – 1194.31(f)
Section 255 – 1193.41(e)(2)(h)
HFDS – 6.4.1.1, 6.4.1.9, 6.4.1.16
160
Users may have difficulty swiping cards through the full length of the card
reader slot.
Detailed Description: Some card readers require users to swipe cards through a slot that is
several inches long. Users with limited reach (due to upper mobility impairments, or due to
interacting with the machine from a wheelchair) may be unable to swipe the card through the
entire slot in one continuous movement, which may result in a card reader error.
Figure 98: The card reader slot is long and is oriented horizontally.
Populations Impacted: Users with upper mobility impairments; users with lower mobility
impairments.
Potential Solutions: Ensure that the card reader slot is fully within the reach envelope of
users. Avoid using card readers with long swipe distances (longer than 6 to 7 inches). Orient
the card slot vertically, which reduces the amount of lateral reach that is required. Locate the
card slot in accordance with the reach ranges defined in section 308 of the ADA-ABA
guidelines.
161
Figure 99: The card reader slot is short and is oriented vertically.
Provide a card reader that can be repositioned by the user. A card reader that can swivel or
slide towards the user may allow users to adjust the card reader into a usable position without
having to reposition themselves.
Provide a reader that requires the user to insert, rather than swipe, the card. Inserting a card
into the reader requires less range of motion than swiping a card.
Provide support for contactless card reading. Contactless cards (which use barcodes or RFID
technology to store data) eliminate the need for the user to swipe the card.
Applicable Guidelines:
ADA-ABA – 308.2.1, 308.2.2, 308.3.1, 308.3.2
Section 508 – 1194.25(j), 1194.31(f)
HFDS – 6.4.1.1, 6.4.1.4, 6.4.1.6, 6.4.1.10, 6.4.1.15
162
Use of multiple user interfaces may cause problems for users.
Detailed Description: Some card readers associated with point of sale machines have a user
interface separate from the primary user interface of the machine. If users begin a transaction
on the primary user interface, and are then expected to complete the transaction using a second
user interface, confusion may result. If the secondary user interface does not provide the
necessary accessibility features, users may have difficulty completing their transactions.
Populations Impacted: Users who are blind; users with low vision; users with cognitive
impairments.
Potential Solutions: Fully integrate the card reader into the primary user interface. A design
where the user can complete the entire transaction through a single user interface is preferable
to one where the user must switch to a different user interface for part of the transaction.
Notify the user when it is necessary to switch to a secondary user interface. The primary user
interface should inform the user (both visually and auditorily) when it is necessary to begin
using a secondary user interface on the card reader device. The user should then be able to
complete the transaction without switching back to the primary interface.
Ensure that the secondary user interface provides all necessary accessibility features. If a
secondary user interface must be used, ensure that the secondary interface also provides all
necessary accessibility features.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(a), 1194.31(b)
HFDS – 6.4.1.16, 6.4.1.22
EITAAC – 5.2.1.9.1, 5.2.1.10.1
163
The card reader does not eject the card far enough for users to grasp it.
Detailed Description: Card readers into which cards are fully inserted may not eject the card
far enough for easy retrieval. Users with upper mobility impairments may find it difficult to
grasp the edge of the protruding card.
Figure 100: The card reader does not eject the card far enough for the user to grasp it.
Populations Impacted: Users with upper mobility impairments.
Potential Solution: Ensure that the card is ejected a sufficient distance from the reader so that
a sufficient area of the card is available for the user to grasp. The card should be ejected far
enough so that users can easily grasp it between the thumb and lateral aspect of the index
finger. Users should not be required to pinch the edge of the card with their fingertips.
Figure 101: The card reader ejects the card far enough for the user to grasp it.
164
Applicable Guidelines:
ADA-ABA – 309.4
Section 508 – 1194.23(k)(2), 1194.25(c), 1194.31(f)
HFDS – 6.4.1.14
165
Insufficient feedback is provided when a user forgets to retrieve a card.
Detailed Description: Users may forget to retrieve cards from card readers at the conclusion of
transactions, especially with card readers into which cards are fully inserted. When this occurs,
the feedback provided by the point of sale machine may be unclear or insufficient.
Populations Impacted: Users who are blind; users with low vision; users with cognitive
impairments.
Potential Solutions: Require the user to remove the card before completing the transaction.
Preventing the completion of the transaction (by not printing a receipt, not dispensing tickets or
other purchases, etc.) until the card has been removed from the card slot will greatly reduce the
likelihood of users forgetting to retrieve credit cards.
Provide a visual and audible alert to the user that the card has not been retrieved. The
machine should remind users via an on-screen message as well as an auditory alert that the card
has not been removed from the card reader. The alert should occur quickly enough (perhaps a
few seconds after the card is able to be retrieved) that the user is notified before moving too far
from the machine. If the machine is attended, notifying the attendant may also be beneficial, so
that the attendant can get the customer’s attention and assist the customer with retrieving the
card.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(a), 1194.31(b)
HFDS – 8.18.3.2, 8.18.4.1
EITAAC – 5.2.1.9.1, 5.2.1.10.1
166
What are the common issues associated with the signature area?
Point of sale machines that accept credit cards for payment typically have an electronic
signature area. Users use a stylus to sign within the signature area, and may also have to use the stylus
for other functions, such as pressing an on-screen “OK” button to accept the signature.
Users may not be sufficiently notified that input is required in the signature
area.
Detailed Description: On some point of sale machines, the signature area is in effect a
secondary user interface, distinct and separate from the primary user interface. Users may not
be sufficiently notified when they need to begin interacting with the signature area (to sign the
screen, accept the signature, or input other information).
Populations Impacted: Users who are blind; users with low vision; users with cognitive
impairments.
Potential Solutions: Notify users when input is required in the signature area. The primary
user interface should prompt the user (both visually and auditorily) when it is necessary to
provide input in the signature area.
Integrate the signature area into the primary user interface. A design where the user can
complete the entire transaction through a single user interface is preferable to one where the
user must switch to a different user interface for part of the transaction. Users will be more
likely to realize that additional input is required if the input can be provided through the
interface they are already working with. If a secondary user interface must be used, ensure that
the need to switch to the secondary interface is clearly communicated, and ensure that all
necessary accessibility features are provided for the secondary interface. Ensure that once the
user switches to the secondary interface, the transaction can be completed through that interface
without switching back to the primary interface.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(a), 1194.31(b)
HFDS – 6.4.1.22, 6.4.1.32, 8.18.3.2, 8.18.4.1
EITAAC – 5.2.1.9.1, 5.2.1.10.1
167
Users may have difficulty locating the signature area.
Detailed Description: The signature area is often part of the card reader, and the location of
the card reader and signature area often varies from machine to machine. Users with visual
impairments may be unsure of where to search for the signature area.
Figure 102: The signature area is not tactilely discernible.
Populations Impacted: Users who are blind; users with low vision.
Potential Solutions: Describe the location of the signature area to the user both visually and
auditorily. Provide both on-screen text and/or graphics and auditory output indicating the
location of the signature area to the user, making use of obvious landmarks on the machine to
establish the location (i.e., “the signature area is below the card reader and is located to the left
of the display screen”).
Ensure that the signature area is tactilely differentiable from the surrounding area. Consider
providing a raised border around the signature area, and ensure that the surface of the signature
area screen is tactilely discernible from the rest of the machine.
168
Figure 103: A raised edge around the signature area improves tactile discernability.
Place the signature area immediately adjacent to the card reader. Because a common
workflow for users will be to swipe a card and then provide a signature, place the signature area
in proximity to the card reader so that users can easily transition from the card reader to the
signature area without having to reorient themselves.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(a), 1194.31(b)
HFDS – 6.4.1.18, 6.4.1.19, 6.4.1.22
169
Users may have difficulty determining the boundaries of the signature area.
Detailed Description: On some point of sale machines, the signature area is a subset of the full
signature area screen, and the boundary of the allowable area is represented graphically and is
not tactilely discernible. If a user’s signature is not fully within the signature area, it may not
be accepted by the machine. Users with visual impairments may be unable to see the boundary
of the allowable area, and may therefore be unable to determine if they are signing within the
boundary.
Figure 104: The signature area only fills a portion of the screen.
Populations Impacted: Users who are blind; users with low vision.
Potential Solutions: Allow users to sign anywhere on the screen. The boundary of the screen
should be tactilely discernible, so if the allowable area for signatures fills the entire screen,
users can use the edges of the screen to determine tactilely where they should sign.
170
Figure 105: The signature area fills the entire screen.
Provide a tactile boundary around the allowable area for signatures. If allowing users to sign
anywhere on the screen is not feasible, then indicate the allowable area with a tactilely
discernible line raised from or etched into the display.
Applicable Guidelines:
Section 508 – 1194.31(a), 1194.31(b)
HFDS – 6.4.1.18, 6.4.1.19
171
Users may have difficulty aligning their signatures within the signature area.
Detailed Description: Many point of sale machines display a graphical line within the
signature area to which users can align their signatures. Because the line is not tactilely
discernible, users with visual impairments may be unable to see the line, and may therefore
have difficultly aligning their signatures appropriately. Users with upper mobility impairments
(particularly those with tremors, or who lack fine motor control) may also have difficulty
aligning their signatures accurately.
Populations Impacted: Users who are blind; users with low vision.
Potential Solutions: Relax requirements on signature alignment. The machine should accept
signatures in any orientation, even if they are not accurately aligned.
Provide tactile marks in the signature area. Indicate the signature alignment line with a
tactilely discernible line that is raised from or etched into the display, or indicate the ends of the
line with a pair of tactile markings. The tactile marks should be prominent enough to be
tactilely discernible, but should not interfere with the use of the stylus.
Provide a clear area around the signature area for users to brace their hands. Providing a
space near the signature area where users can brace their hands to steady themselves and reduce
tremors can help users sign within the signature area more accurately.
Applicable Guidelines:
Section 508 – 1194.31(a), 1194.31(b), 1194.31(f)
HFDS – 6.4.1.16, 6.4.1.18, 6.4.1.19
172
What are the common issues associated with output areas?
Point of sale machines often provide one or more tangible items of output to users. Outputs
may include money (bills and coins), receipts, and other products that result from transactions with the
machine (for example, tickets, boarding passes, coupons, etc.). The outputs are dispensed into one or
more output areas, which vary widely in design.
Users may have difficulty locating output areas.
Detailed Description: The number, type, and style of output areas varies among point of sale
machines, and this lack of consistency can make it difficult for users to find the output area(s)
to retrieve outputs.
Figure 106: Output areas are located in several different locations on the device.
Populations Impacted: Users who are blind; users with low vision.
Potential Solutions: Dispense all outputs into a single area. Instead of providing separate
output areas for each type of output produced by the machine, consider dispensing all outputs
into a single area, so that the user only has to locate one component in order to retrieve all
output products.
Collocate all output areas. If it is not feasible to dispense all outputs into a single area,
consider grouping all of the output dispensers together on the machine.
173
Figure 107: All of the output areas on the device are collocated.
Ensure that the output area is easy to distinguish from the rest of the machine. The output area
should be prominently located on the machine, so that a searching user can find it quickly, and
it should be tactilely identifiable. Avoid covering output with a door that the user must open;
the door may hinder the ability of users to locate the output area by touch. The visual
appearance of the output area should contrast with the machine, to assist users with low vision
to locate it.
Provide tactile labels. The output area should be clearly labeled with a Braille label, raised
text, or other tactile markings.
Describe the location of the output area to the user both visually and auditorily. Provide both
on-screen text and/or graphics and auditory output indicating the location of the output area to
the user, making use of obvious landmarks on the machine to establish the location (i.e.,
“change is dispensed below the payment area”).
Use an indicator light to draw a user’s attention to the output area. When outputs are
dispensed, illuminate a light in the output area to indicate its location and attract the attention of
the user.
Applicable Guidelines:
ADA-ABA – 707.5
Section 508 – 1194.31(a), 1194.31(b)
Section 255 – 1193.41(a)(3)(b), 1193.41(i)(2)(a)
HFDS – 6.4.1.16, 6.4.1.18, 6.4.1.22, 6.4.1.28, 6.4.1.30
174
Users are not sufficiently notified when outputs are present in the output area.
Detailed Description: On some point of sale machines, no indication that outputs have been
dispensed (other than sounds associated with the dispensing, such as coins falling into the coin
output tray) is provided. This may result in users failing to realize that there are outputs that
need to be retrieved, and leaving them behind when they complete their transactions.
Figure 108: Change is hidden behind a door, and cash is not clearly visible in the cash tray.
Populations Impacted: Users who are blind; users with low vision; users who are deaf; users
who are hard of hearing; users with cognitive impairments.
Potential Solutions: Prompt the user to retrieve output, both visually and auditorily. Provide
both on-screen text and/or graphics and auditory output indicating that outputs have been
dispensed, and describing the location of the output area to users. Consider providing a light in
or near the output area that illuminates to indicate the presence of outputs and to indicate the
location of the output area.
Repeat prompts if outputs are not retrieved in a timely manner. If outputs remain in the output
area after some period of time after the initial prompt (long enough to not be a nuisance to the
user, but short enough that the user is notified before moving too far from the machine), prompt
the user that there are still outputs that need to be retrieved. If the machine is attended,
notifying the attendant may also be beneficial, so that the attendant can get the customer’s
attention and assist the customer with retrieving the items.
When possible, dispense all outputs into a single area. This enables users to retrieve all outputs
at the same time, and avoids situations where users retrieve output from one area but forget to
check other areas.
Ensure that outputs are clearly visible within the output area. Users should be able to tell at a
glance if outputs are present in the output area. Outputs should be visible from either a seated
or standing position.
175
Figure 109: Outputs are clearly visible within the output area.
Ensure that outputs are tactilely discernible within the output area. Design output areas so that
users can quickly determine by touch if outputs are present. Ensure that outputs are ejected a
sufficient distance from the machine to be tactilely located. Ensure that the output area does
not provide any way for outputs to become hidden (for example, by slipping too far away from
the opening of the output area).
Applicable Guidelines:
ADA-ABA – 707.5, 707.5.1
Section 508 – 1194.31(a), 1194.31(b), 1194.31(c)
HFDS – 6.4.1.12, 8.18.4.2
EITAAC – 5.2.1.9.1, 5.2.1.10.1
176
Users have difficulty retrieving outputs from the output area.
Detailed Description: Various aspects of the design of the output area, such as obstructions,
the depth of the area, and the output ejection distance, may interfere with users’ ability to
retrieve outputs from the output area, especially for users with upper mobility impairments.
Figure 110: Cash and change are difficult to retrieve from the output areas.
Populations Impacted: Users with upper mobility impairments.
Potential Solutions: Ensure that the outputs are ejected a sufficient distance from the machine
to facilitate grasping by users. When paper outputs such as receipts or tickets are output
through a slot, ensure that enough of the item protrudes from the machine so that users can
easily grasp it between the thumb and the lateral aspect of the index finger. Users should not
be required to pinch the edge of the item with their fingertips.
Provide a cutout in output trays so that items can be grasped for removal. When paper outputs
such as cash or receipts are dropped into an output tray, provide an open cutout in the tray that
allows users to grasp the items from above and below for removal.
177
Figure 111: Cash and change are easy to grasp and remove from the output areas.
Ensure that the design of the output area does not interfere with removal of the outputs. Avoid
covering the output area with a door that users must hold open while retrieving outputs. When
coins, tokens, or other non-paper items are dispensed, design the output area to allow users to
easily scoop the items out of the output area, without interference from a lip or other
obstruction in the output area.
Applicable Guidelines:
ADA-ABA – 309.4
Section 508 – 1194.31(f)
HFDS – 6.4.1.12
178
What are the common issues associated with the writing and temporary
storage areas?
Some point of sale machines provide a flat, clear space that users can use for temporary storage
of personal items (purses or wallets, paperwork, etc.) while using the machine, or as a writing or work
surface (for writing checks, affixing stamps, etc.).
No space for writing or temporarily placing belongings is provided.
Detailed Description: Any user may have items in his or her hands when using a point of sale
machine that they would like to temporarily put down in order to interact with the machine.
Users with disabilities may have particular needs in this area – for example, a user with low
vision might need to retrieve a magnifier from a bag, or a user with an upper mobility
impairment might have only one functional hand to carry items and to interact with the
machine. Providing temporary storage space (for example, a small shelf) is beneficial,
especially for certain types of machines such as postal kiosks, where the user is likely to have
one or more items in hand when approaching the machine. If transactions with the machine
require the user to write (to sign a receipt, fill out a form, etc.), the lack of a writing area makes
it difficult for users to write legibly.
Populations Impacted: All users.
Potential Solutions: Provide an area where users can temporarily place their belongings. The
storage area should be large enough to accommodate the sorts of items that users might
typically carry in their hands (purses, umbrellas, etc.), and should allow users to place the items
in a location that does not interfere with access to the machine.
Figure 112: An appropriate area for writing or placing belongings is provided.
Provide a writing surface. If transactions with the machine are likely to require the user to
write, provide a surface on which the user can place the paper for writing. The writing area
179
should be large enough to accommodate the paper and also allow room for the user’s hands
while writing.
Applicable Guidelines:
Section 508 – 1194.31(f)
HFDS – 6.4.1.1
180
The storage or writing area is too high or too low to be accessible to all users.
Detailed Description: Users with lower mobility impairments who use wheelchairs or other
personal mobility devices have different reach abilities than standing users. Writing and
temporary storage areas provided on a point of sale machine at a height that is acceptable for
standing users might be out of reach for seated users.
Populations Impacted: Users with lower mobility impairments.
Potential Solutions: If a single writing and/or storage space is provided for all users, ensure
that it is at a height that can be used by both seated and standing users. The storage/writing
area should be located at a height between 28” and 34” above the ground and no more than 10”
behind the most forward point of the device surface in order to accommodate the needs of
wheelchair users.
Provide separate writing and/or storage areas for seated versus standing users. If the design
of the machine does not allow placement of a single storage/writing area that is usable by both
seated and standing users, consider providing separate areas for standing and seated users. The
area intended for seated users should conform to the location guidance above.
Applicable Guidelines:
ADA-ABA – 308.2.1, 308.2.2, 308.3.1, 308.3.2, 902.3, 904.3.3
Section 508 – 1194.25(j)
181
What are the common issues associated with the supplies area?
Some transactions with point of sale machines may require the use of supplies such as forms,
envelopes, or mailing labels. When this is the case, the point of sale machines often have a “supplies
area” in which necessary supplies are stored.
Users may have difficulty locating the supplies area.
Detailed Description: The design or location of the supplies area may make it difficult for
users to locate the supplies area, especially if the supplies area is not clearly labeled.
Figure 113: The supplies area is unlabeled and not prominently located.
Populations Impacted: Users who are blind; users with low vision.
Potential Solutions: Ensure that the supplies area is prominently located. The supplies area
should be located in a prominent location on the machine that is visible from a seated or
standing position when the user is in a typical location for using the machine.
182
Figure 114: The supplies area is clearly labeled and prominently located.
Label the supplies area clearly with text and tactile labels. Provide text labels for sighted
users, and tactile labels (Braille or raised lettering) to provide cues to users with visual
impairments.
Avoid obscuring the supplies area with covers, doors, or overhanging parts of the device. Such
obscurations make it more difficult for users to locate the supplies by touch.
Applicable Guidelines:
Section 508 – 1194.31(a), 1194.31(b)
Section 255 – 1193.41(a)(2)(b), 1193.41(a)(2)(c)
HFDS – 6.4.1.12, 6.4.1.22, 6.4.1.27, 6.4.1.28
183
Doors and covers make it difficult for users to retrieve supplies.
Detailed Description: Access to the supplies area may be blocked by doors or covers,
requiring users to open a door or lift a cover to obtain supplies. Some users with upper
mobility impairments may only have the use of one hand, or may have limited strength or fine
motor control, making it difficult for them to simultaneously open a door or cover and retrieve
supplies.
Figure 115: Access to the supplies is obstructed by a door.
Populations Impacted: Users with upper mobility impairments.
Potential Solution: Avoid obstructing access to the supplies area with doors or covers. If a
door or cover is necessary, ensure that it is possible to open the door or cover and retrieve
supplies with one hand. For example, provide a cover that does not close automatically, so that
the user can first open the cover and then retrieve supplies without having to hold the cover
open.
184
Figure 116: Access to the supplies area is unobstructed by a door or cover.
Applicable Guidelines:
ADA-ABA – 309.4
Section 508 – 1194.31(f)
HFDS – 6.4.1.6, 6.4.1.14
185
The design of the supplies area makes it difficult for users to reach or grasp the
supplies.
Detailed Description: The size of the supplies area or features such as a raised lip in front of a
stack of forms may make it difficult for users to access the supplies and grasp them for
removal, especially for users with limited reach or limited fine motor control. The size of the
opening into which users must reach to access supplies may be too small, limiting access for
users who use a reaching aid or the side of a fist to manipulate the supplies. The supplies area
may be too deep, allowing items to be pushed away from the opening and requiring users to
reach far into the opening to retrieve supplies. A raised lip or similar feature at the front edge
of the supplies area may make it difficult for users to slide supplies out of the storage area so
they can be grasped.
Figure 117: The opening to the supplies area is too small.
Populations Impacted: Users with upper mobility impairments.
Potential Solutions: Provide an opening into the supplies area that is large enough to
accommodate a user’s hand or a reaching aid. Consider that users may need to use the side of
a fist or a reaching aid, rather than simply the fingers, to manipulate the supplies.
186
Figure 118: The opening to the supplies area is large enough to accommodate a hand or reaching aid.
Ensure that supplies remain easily accessible at the front edge of the supplies area. The goal is
to avoid requiring users to reach more than an inch or two into the supplies area to access the
supplies. Therefore, design the depth of the supplies area so that supplies cannot move away
from the front edge of the area. If the size of the supplies varies, consider using an adjustable
backstop that can be moved to accommodate supplies of different sizes.
Design the supplies area in a way that helps the user grasp supplies for retrieval. For example,
design a dispenser that provides a single envelope or form at a time, and that allows the item to
protrude so that users can pinch it for removal.
Applicable Guidelines:
ADA-ABA – 309.4
Section 508 – 1194.31(f)
HFDS – 6.4.1.12
187
What are the common issues associated with the trash receptacle?
Some point of sale machine transactions will produce trash, such as receipts, coupons, or other
output. It may be desirable to provide a receptacle for the disposal of trash for the convenience of
users.
Locating the trash receptacle may be difficult for some users.
Detailed Description: Some trash receptacles provide only a small slot for access (to prevent
users from depositing large items); others have a door covering the opening. Not all point of
sale machines provide trash receptacles, and on those that do, the placement of the trash
receptacle varies. These factors can make it difficult for users with visual impairments to find
the trash receptacle.
Figure 119: The trash slot is located on the side of the machine and is not clearly labeled.
Populations Impacted: Users who are blind; users with low vision.
Potential Solutions: Locate the trash receptacle in a logical and convenient area. For
example, if the point of sale machine produces output that users may desire to discard, consider
placing the trash receptacle in proximity to the output slot. Care should be taken, however, to
ensure that the trash receptacle will not be confused with an input or output slot. Placing the
receptacle on the side of the machine or low on the machine (around wastebasket height) may
help differentiate it from other components.
188
Figure 120: The trash receptacle is located on the front of the machine and is clearly labeled.
Clearly label the trash receptacle. The trash receptacle should be clearly labeled with text, as
well as with Braille or raised lettering. If possible, avoid placing tactile labels in areas that are
likely to be dirty (e.g., too close to the access slot, or directly on the door covering the
opening).
Applicable Guidelines:
Section 508 – 1194.31(a), 1194.31(b)
Section 255 – 1193.41(a)(2)(b), 1193.41(a)(2)(c)
HFDS – 6.4.1.22, 6.4.1.26, 6.4.1.28
189
If the trash receptacle is covered, users may have difficulty depositing trash.
Detailed Description: The trash receptacle may be covered by a door that must be opened
before trash can be deposited. Simultaneously opening the door and depositing trash may be
difficult for users with upper mobility impairments. If the door mechanism is complex, or if
high levels of force are required to operate it, the problems are exacerbated.
Figure 121: The trash receptacle is covered by a door.
Populations Impacted: Users with upper mobility impairments.
Potential Solutions: Provide an uncovered, open slot that drops into a trash container. An
uncovered trash slot restricts the size of trash that can be deposited, but allows for easy, onehanded use. This avoids the problem of having to simultaneously open the cover and deposit
trash, which may be difficult for users with upper mobility impairments. Care should be taken
with the design and placement of the slot to ensure that it will not be confused with an input or
output slot, however.
190
Figure 122: The trash receptacle is an uncovered, open slot.
If a cover is used, ensure that the door is simple to operate with one hand. A swinging door
that can be pushed in with one hand is preferable to a more complex sliding or rotating
mechanism. The door should also open without excessive force (less than 5 pounds). This
makes the door easier to operate for users with limited strength, and reduces the possibility of a
user’s hand being pinched by a closing door.
Applicable Guidelines:
ADA-ABA – 309.4
Section 508 – 1194.23(k)(2), 1194.25(c), 1194.31(f)
HFDS – 6.4.1.12
191
References
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Handbook of Human Factors, John Wiley & Sons, New York, NY, 1988.
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1993.
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to address the needs of older persons and persons with disabilities, ISO/IEC, Geneva,
Switzerland, 2001.
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219bis Guidebook, COST 219bis, European Commission, 1999.
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available.)
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Department of Defense, 1999.
11. National Council on Disabilities, Design for Inclusion: Creating a New Marketplace.
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(2006).
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York, NY, 1993.
17. United States Access Board, Americans with Disabilities Act and Architectural Barriers Act
Accessibility Guidelines (ADA-ABA AG), Washington, D.C., 2004.
18. United States Access Board, Electronic and Information Technology Access Advisory
Committee (EITAAC), Recommendations for Accessibility Standards: Electronic and
Information Technology, Washington, D.C., 1999.
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Final Rule, 36 CFR Part 1194, Federal Register, 65.246 (2000).
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CFR Part 1193, Federal Register, 63.22 (1998).
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Handbook of Human Factors and Ergonomics, John Wiley & Sons, New York, NY, 1997.
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192
Appendix A: Checklist Evaluation
Disability
Evaluator Instructions
Operable with limited Set an account code up which requires user access before
cognitive skills or
use. Where possible, verify user settings are individually
language facility
customized (where settings are activated by a user control
card or sign-in procedure) such that the system can be
autoconfigured to match different user preferences.
Operable with limited Verify that optional voice control is provided.
cognitive skills or
language facility
Operable from a
Determine whether forward reach is unobstructed. If so,
seated position
verify that the high forward reach is a maximum of 48
inches and the low forward reach is a minimum of 15
inches.
Operable from a
Determine whether forward reach is obstructed. If so, verify
seated position
that the clear floor space extends beneath the element for a
distance not less than the required reach depth over the
obstruction. Determine the reach depth. If the reach depth
is 20 inches (510 mm) or less, verify that the high forward
reach does not exceed 48 inches (1220 mm). If the reach
depth is greater than 20 inches (510 mm), verify that it is no
greater than 25 inches (635 mm) and that the high forward
reach does not exceed 44 inches (1120 mm).
Operable from a
Determine whether side reach is unobstructed and whether
seated position
a parallel approach is allowed. If so, verify that the high
side reach is a maximum of 48 inches (1220 mm) and a
minimum of 15 inches.
Operable from a
Determine whether side reach is obstructed and a parallel
seated position
approach is allowed. Determine the reach depth. If the
reach depth is 10 inches (255 mm) or less, verify that the
high side reach does not exceed 48 inches (1220 mm). If
the reach depth is greater than 10 inches (255 mm), verify
that it is no greater than 24 inches (610 mm) and that the
high side reach does not exceed 46 (1170 mm) inches.
Operable with all
Verify that this self-contained product is usable by people
disability types
with disabilities, without requiring the use of assistive
technologies. Verify that the product does not require the
end-user to attach assistive technology to the product.
Operable with all
Identify any time-out situations. Verify that if a timed
disability types
response is required, the user is alerted and given sufficient
time (adjusted by the user over a range equal to at least 5
times the average user setting with a value of at least 5
seconds) to indicate that more time is required. Verify that
response times can be adjusted or that a non-timed
alternative is available.
Guideline Source
Section 255
1193.41(i)(2)(d) - Advisory
Guidance
Section 255
1193.41(f)(2)(b) - Advisory
Guidance
ADA-ABA AG
308.2.1
ADA-ABA AG
308.2.2
ADA-ABA AG
308.3.1
ADA-ABA AG
308.3.2
Section 508
1194.25(a)
Section 508
1194.22(p)
1194.23(d)
1194.25(b)
Section 255
1193.41(g)(2)(a)
1193.41(g)(2)(b) - Advisory
Guidance
EITAAC
5.2.1.7.1
193
Disability
Operable with
complete blindness
Operable with some
vision loss
Operable with
complete blindness
Operable with all
disability types
Operable from a
seated position
Operable from a
seated position
Operable from a
seated position
Operable with all
disability types
Operable with all
disability types
Evaluator Instructions
Guideline Source
5.3.4.3
Section 508
For all controls, verify that controls and keys are tactilely
discernible without activating the controls or keys.
1194.23(k)(1)
1194.25(c)
1194.26(a)
1194.26(b)
Section 508
For all controls, identify any locking or toggle controls or
keys. Verify that the status of any locking or toggle control 1194.23(k)(4)
keys is visually discernible, and discernible either through 1194.25(c)
touch or sound.
1194.26(a)
1194.26(b)
Section 508
Identify whether the device uses biometric forms of user
identification or control. Verify that when biometric forms of 1194.25(d)
user identification or control are used, an alternative form of 1194.26(c)
identification or activation is available, which does not
EITAAC
require the user to possess particular biological
characteristics. Assumption: Providing a password
5.2.1.13
capability is an acceptable alternative.
Section 508
Determine whether the device has operable controls, is
freestanding, non-portable, and intended to be used in one 1194.25(j)(2)
location. Identify any operable controls, and measure their
distance from the reference plane (defined in 1194.25(j)(1)
and the associated figure). If the control is 10 inches or
less behind the reference plane, verify that the height of the
control is a maximum of 54 inches, and a minimum of 15
inches above the floor. Assumption: Operable controls do
not include voice operated controls.
Section 508
Determine whether the device has operable controls, is
freestanding, non-portable, and intended to be used in one 1194.25(j)(3)
location. Identify any operable controls, and measure their
distance from the reference plane (defined in 1194.25(j)(1)
and the associated figure). If the control is more than 10
inches, and not more than 24 inches behind the reference
plane, verify that the height of the control is a maximum of
46 inches, and a minimum of 15 inches above the floor.
Assumption: Operable controls do not include voice
operated controls.
Section 508
Determine whether the device has operable controls, is
freestanding, non-portable, and intended to be used in one 1194.25(j)(4)
location. Identify any operable controls, and measure their
distance from the reference plane (defined in 1194.25(j)(1)
and the associated figure). Verify that there are no
operable controls more than 24 inches behind the reference
plane. Assumption: Operable controls do not include voice
operated controls.
Section 255
Identify all accessibility features. Verify that an option
exists to switch each accessibility feature ON/OFF (such
1193.35(3)(c) - Advisory
that multiple features could be on at once or only one
Guidance
feature could be on at a given time, depending on user
needs).
Identify display options. Verify that information (things the Section 255
display presents to us) is presented in as many redundant 1193.35(1)
194
Disability
Operable with all
disability types
Operable with all
disability types
Operable with all
disability types
Operable with all
disability types
Operable with all
disability types
Operable with all
disability types
Operable with all
disability types
Operable with all
disability types
Operable with all
disability types
Operable with all
disability types
Operable with all
disability types
Operable with all
disability types
Operable with all
disability types
Evaluator Instructions
forms as possible (i.e., allows the use of visual, aural, and
tactile strategies). When audio information is important for
the use of the product, verify that the information is also
provided visually, and, where appropriate, tactilely. Verify
that multiple modes are available for controls as well.
Verify that systems and equipment have standardized
terminology, look, and feel (e.g., use established layouts for
keyboards and keypads).
Identify error conditions. Verify that systems are tolerant of
human errors.
Identify documentation of unsafe operating states and
actions. Verify that systems and equipment clearly identify
safe and unsafe operating states and actions.
Identify all warning labels. Verify that design, location,
procedural guidance, and suitable warning labels are
provided to prevent damage to equipment while it is being
handled, installed, operated, or maintained.
Identify situations which require mounting or alignment.
Verify that equipment includes physical features that
prevent improper mounting or alignment, or at least has
labels or codes to identify proper mounting and alignment.
Identify any user feedback. Verify that systems and
equipment provide timely and informative feedback to user
actions to keep the users informed about what is
happening.
Identify and implement control actions and observe the
outcome of each control action. Verify that user actions
cause predictable results.
Identify all labeling and instructions on the device. Verify
that systems and equipment use terms and images familiar
to the user.
Identify all control actions. Verify that systems and
equipment are designed to minimize hand and eye
movements, thus maximizing efficiency.
Determine whether help information is provided. Verify that
help is available in the event that the user has difficulty
operating or maintaining software, systems or equipment.
Identify controls used solely for maintenance and
adjustment. Verify that, in general, controls used solely for
maintenance and adjustment are covered during normal
equipment operation, but are readily accessible and visible
to a user when required.
Identify all controls. Verify that controls are designed and
located so that they are not susceptible to being moved
accidentally or inadvertently, particularly critical controls
where such operation might cause equipment damage,
personnel injury, or system performance degradation.
Identify all labels. Verify that the characters identifying
controls and displays are larger than the characters
identifying control positions.
195
Guideline Source
EITAAC
5.2.1.4.2
Vanderheiden, 1997
HFDS
2.4.5
Vanderheiden, 1997
HFDS
2.5.4
HFDS
2.5.6
HFDS
2.5.10
HFDS
2.5.11
HFDS
2.6.1
HFDS
2.6.2
HFDS
2.6.3
HFDS
2.6.8
HFDS
2.7.1
HFDS
6.1.1.3.7
HFDS
6.1.1.6.1
HFDS
6.1.2.1.4
Disability
Operable with all
disability types
Operable with all
disability types
Operable with all
disability types
Operable with all
disability types
Operable with all
disability types
Operable with all
disability types
Operable with all
disability types
Operable with
complete blindness
Operable with some
vision loss
Operable with
complete blindness
Operable with some
vision loss
Operable with
complete blindness
Operable with
complete blindness
Operable with
complete blindness
Operable with some
Evaluator Instructions
Identify all labels. Verify that labels are not located where
they obscure other information needed by the user or where
a control or user’s normal hand or arm position will obscure
the label.
Identify all labels. Verify that labels are placed very near
the control that they identify.
Identify all labels. Verify that labels are placed above the
control they describe, or when located above eye level, may
be located below the control if label visibility will be
enhanced.
Identify all labels. Verify that labels are oriented so that
alphanumeric characters are read horizontally from left to
right.
Identify any use of abbreviations. Verify that abbreviations
are used in labels only if they are familiar to the users.
Identify any use of labels and compare the wording to that
used in documentation. Verify that designations and terms
used on labels are consistent with designations and terms
in user documentation and parts catalogs.
Identify whether the device provides voice output. Verify
whether the audio signal is provided at a standard signal
level through an industry standard connector that will allow
for private listening. Verify that the product provides the
ability to interrupt, pause, and restart the audio at any time.
Assumption: 2.5 mm or 3.5 mm jack are the industry
standard audio connectors.
Verify that at least one mode of operation and information
retrieval is provided which does not require user vision; or,
alternatively, that support for assistive technology used by
people who are blind or visually impaired is provided.
Inspect the machine and verify that an optional remote
audiovisual indicator of display information has been
provided (and is tactile, if appropriate).
Determine whether voice output is available. If so, turn the
feature on, and interact with the controls to test the use of
voice. Verify that voice output (turned on/off as needed) is
available to “speak” the names of keys or buttons (but does
not activate them) as they are encountered. Determine
whether voice output is descriptive.
Identify all controls and their shape. Verify that the shapes
of controls are associated with their functions.
Verify that sufficient space for easy tactile location,
identification, and labeling (e.g., large print (~ 18 point) or
Braille) has been provided on all sides of controls. NOTE:
Georgia Tech has determined that a more practical
196
Guideline Source
HFDS
6.1.2.2.2
HFDS
6.1.2.2.3
HFDS
6.1.2.2.4
HFDS
6.1.2.2.13
8.2.11.4.13
HFDS
6.1.2.4.5
HFDS
6.1.2.4.6
Section 508
1194.25(e)
EITAAC
5.2.1.11
Section 508
1194.31(a)
Section 255
1193.41(a)
EITAAC
5.2.1.1
Vanderheiden, 1997
Section 255
1193.41(a)(3)(c) - Advisory
Guidance
Vanderheiden, 1997
Vanderheiden, 1997
Disability
vision loss
Operable with
complete blindness
Operable with some
vision loss
Operable with
complete blindness
Operable with
complete blindness
Operable with
complete blindness
Operable with
complete blindness
Operable with all
disability types
Operable with
complete blindness
Operable with limited
manual dexterity
Operable with
complete blindness
Operable with limited
strength and reach
Operable with
complete blindness
Operable with
complete blindness
Evaluator Instructions
Guideline Source
evaluation is to verify that there is room on the control itself
or on at least one side of the control.
Section 255
Inspect each control. Verify that Braille labels or raised
lettering are used to identify controls.
1193.43(a)(2)(b&c) Advisory Guidance
Press each key type. Verify that snap action feedback (“a
gradual increase followed by a sharp decrease in force
required to actuate the key, and a subsequent increase in
force beyond this point for cushioning” – force 0.25 to 1.5 N
or 28 g to 142 g (0.06 lb to 0.34 lb)) is provided for key
presses. Measure the pressure required to activate the
function.
Note whether membrane or zero travel keys have been
used (they should be avoided). Identify keys which are not
membrane or zero travel keys. Measure travel distance for
each and verify that it is between 1.3 to 6.4 mm.
Identify buttons that are not part of the touchscreen display.
Verify that buttons are discrete, and can be felt and located
by touch by inspecting the controls without vision. Flat
panel buttons should have a raised lip or edge around
each. Inspect the keypad and keyboard and verify that
tactile landmarks (“nibs”) have been placed on the “F” and
“J” keys on a keyboard, and on the “5” key on a numeric
keypad. (GT comment - diameter changes (gap between
buttons) of at least 3/8” and thickness changes of at least
1/32” are the most readily detectable.)
Test the control panel mapping under different conditions
(modes) and verify that it does not change unless adjusted
by the user.
Inspect each key and verify that matte, anti-glare, rubbery
material is used for keys.
Inspect each key and measure and verify that keys used for
typing tasks have tops of 1.27 sq cm.
Mercinelli 2.4
Inspect each key and verify that keycaps are easily
interchangeable.
Inspect each control function and verify that direct keypad
input is possible, particularly if controls are located on
different parts of the product.
Inspect each control and verify that buttons which are
activated by the first touch are avoided, and where they
cannot be avoided, include a “confirm” function.
Vanderheiden, 1997
Identify tactile and auditory cues for key activation. For
keypads, provide clear tactile and auditory feedback. If a
touchscreen is used, verify that auditory cues are available
to aid navigation.
197
Mercinelli 2.4
Section 255
1193.41(a)(3)(a) - Advisory
Guidance
EITAAC
5.3.1.9
Mercinelli 2.4
Mercinelli 2.4
Section 255
1193.41(f)(2)(a) - Advisory
Guidance
Section 255
1193.41(a)(3)(e)
1193.41(e)(2)(e) - Advisory
Guidance
Mercinelli 2.4
Disability
Operable with
complete blindness
Operable with
complete blindness
Operable with some
vision loss
Operable with
complete blindness
Operable with
complete blindness
Operable with some
vision loss
Operable with
complete blindness
Operable with some
vision loss
Operable with
complete blindness
Operable with some
vision loss
Operable with
complete blindness
Operable with some
vision loss
Evaluator Instructions
If a flat membrane panel cannot be avoided, verify that a
stick-on tactile overlay providing tactile demarcation of key
locations and functions has been provided or that some
type of audio or tactile feedback is available.
Identify insertable objects. Verify that insertable objects
that are not self-orienting have tactile indicators that show
the proper insertion orientation. Verify that there is visual
contrast between the insertion point and the rest of the
device.
Attach external connectors. Verify that additional tactile
and acoustic (click) feedback is provided from equipment
when external connectors or cards or drawers are properly
connected or inserted.
Determine whether the equipment is intended to be
accessible to the visually impaired. Verify that there is a
nonvisual means for differentiating controls such as by
correlating size, shape, or texture with importance or
function.
Section 255
1193.41(a)(3)(d) - Advisory
Guidance
Vanderheiden, 1997
Mercinelli 2.7
HFDS
6.4.1.19
Section 255
1193.41(a)(3)(b) - Advisory
Guidance
Vanderheiden, 1997
HFDS
Determine whether the equipment is intended to be
accessible to the visually impaired. Verify that there is
6.4.1.20
adequate space for tactile localization and identification and
labeling with large print or Braille.
HFDS
Identify controls that are not accessible to the visually
impaired. Verify that there is an alternative means of
6.4.1.24
manipulation such as a redundant speech recognition input
option.
Identify controls and their functions. Verify that controls are
arranged in groups that facilitate tactile identification.
Identify whether the product permits the user to adjust color
and contrast settings. Verify that a range of color selections
for producing a variety of contrast levels is available; in
Operable with little or particular, that there are at least three color combinations
no color perception
that will provide a high contrast color scheme, and that
there is a combination that will provide a soft background,
low contrast color scheme.
Operable with some Verify that at least one mode of operation and information
vision loss
retrieval that does not require visual acuity greater than
20/70 is provided in audio and/or enlarged print output; or,
alternatively, that support for assistive technology used by
people who are visually impaired is provided.
Operable with some
vision loss
Operable with some
Guideline Source
Vanderheiden, 1997
HFDS
6.4.1.30
Section 508
1194.21(j)
1194.22(m)
1194.25(h)
Section 508
1194.31(b)
Section 255
1193.41(b)
EITAAC
5.2.1.2.1
5.2.1.2.2
Verify that sufficient illumination of controls and instructions Vanderheiden, 1997
has been provided.
Verify that a video jack has been provided for attaching
Vanderheiden, 1997
198
Disability
vision loss
Operable with some
vision loss
Operable with some
vision loss
Operable with some
vision loss
Operable with some
vision loss
Evaluator Instructions
larger-image displays or assistive devices.
Inspect the control space and verify that the space between
letters of words (1/16 of uppercase letters), lines of text,
and differing topics is uniform and maximizes contrast.
Inspect each aspect of the display and verify that the use of
lightweight, extra bold, and condensed typefaces has been
avoided or minimized.
Inspect each aspect of the display and verify that high
contrast (contrast must be greater than 70%) between text
or graphics and background has been used. Also verify
that text and symbols are as simple and large as possible.
If the display is an LCD, verify that the viewing angle is
adjustable.
Operable with from a
seated position
Operable with little or Identify colors that are used. Verify that there is at least
no color perception
one mode that does not require user color perception.
Verify that colors with low luminance are not used.
Operable with some
vision loss
Inspect each display and output format (including control
labels) to verify that color-coding is not used as a primary
coding technique (i.e., redundant color-coding has been
used).
Operable with little or Inspect each display and output format to verify that the
no color perception
color blue, green, or violet is not used to convey
information.
Operable with little or Inspect each display and output format to verify that
no color perception
multicolor combinations red/green, yellow/blue, red/brown,
blue/green, white/light green are not used.
Operable with little or Inspect each control label to verify that an alternative to
no color perception
seeing color is provided. For example, verify that control
identification is coded by relative shape or position, or
graphic labels, in addition to color-coding.
Guideline Source
Section 255
1193.41(b)(2)(b) - Advisory
Guidance
Mercinelli 2.1
Section 255
1193.43(b)(2)(a) - Advisory
Guidance
EITAAC
5.2.1.2.4
Vanderheiden, 1997
Section 255
1193.41(c)(2)(d) - Advisory
Guidance
EITAAC
5.2.1.3
Section 255
1193.41(b)(2)(d) - Advisory
Guidance
EITAAC
5.3.2.8
Vanderheiden, 1997
Section 255
1193.41(c)(2)(b) - Advisory
Guidance
Section 255
1193.41(c)(2)(a) - Advisory
Guidance
EITAAC
5.3.2.8
Prevention of visually Measure screen flicker. Verify that screen flicker does not Section 508
induced seizures
occur between 2 Hz and 55 Hz (or is adjustable outside this 1194.25(i)
range).
Section 255
Prevention of visually Verify that bright flashes which occupy a large part of the
induced seizures
visual field are avoided to minimize the impact on the visual 1193.43(f)(3) - Advisory
cortex.
Guidance
Operable with
Verify that at least one mode of operation and information Section 508
complete deafness
retrieval that does not require user hearing is provided; or, 1194.31(c)
alternatively, that support for assistive technology used by
199
Disability
Operable with some
hearing loss
Operable with
complete deafness
Operable with some
hearing loss
Operable with
complete deafness
Operable with some
hearing loss
Operable with
complete deafness
Operable with some
hearing loss
Operable with
complete deafness
Operable with some
hearing loss
Operable with
complete deafness
Operable with some
hearing loss
Operable with some
hearing loss
Operable with some
hearing loss
Operable with all
disability types
Evaluator Instructions
people who are deaf or hard of hearing is provided.
Guideline Source
Section 255
1193.41(b)
EITAAC
5.2.1.4.1
Mercinelli 2.4
Identify any lights that are used (LED or other stand-alone
types of illumination). Determine when/if they flash or are
steady. Verify that when lights are used as prominent
visual indicators that a steady light represents a continuous
condition and a flashing light represents a new condition.
Identify any use of flash, and measure the rate of flash.
Mercinelli 2.4
Verify that flash rate is between 3-10 flashes/sec with equal
intervals of light and dark.
Identify text versions of auditory information. Verify that all
text versions of auditory information are easily visible and
preserved intact (GT comment - all styles and exact timing
and synchronization commands are maintained and there is
zero introduction of errors or garbling of data; that is,
message is either all numbers or the message is mixed
numbers with text).
Identify all auditory cues that are used. Verify that
additional visual or tactile cues are used when auditory
cues are used to attract a users attention to product
alerts/messages.
Section 255
1193.43(d)(2)(d) - Advisory
Guidance
Determine whether flashing lights are used. If a flashing
light is used to indicate different system modes, verify that
no more than 3 different flash rates are used.
Mercinelli 2.4
Identify whether audio information is important for the use
of the product. Verify that at least one mode of operation
and information retrieval is provided in an enhanced fashion
(with increased amplification); or, alternatively, that support
for assistive hearing devices is provided.
Section 508
1194.31(d)
Identify whether the device will deliver voice output in a
public area. Measure the voice output level. Verify that
incremental volume control is available with output
amplification up to a level of at least 65 dB. Measure the
ambient noise level of the environment. If the ambient
noise level is above 45 dB, verify that a volume gain of at
least 20 dB above the ambient level is user selectable.
Verify that a function is provided to automatically reset the
volume to the default level after every use.
Verify that, when a product delivers audio output through an
external speaker, an industry standard connector for
200
Section 255
1193.43(d)(2)(a) - Advisory
Guidance
Section 255
1193.41(b)
1193.43(e)
EITAAC
5.2.1.5.1
Section 508
1194.23(g)
1194.25(f)
EITAAC
5.2.1.5.4
Section 255
1193.43(g)(2) - Advisory
Disability
Evaluator Instructions
headphones or personal listening devices (e.g., phone-like
handset or ear cup) is provided which cuts off the speaker
when used; an exception is simple auditory information that
is also provided visually. Verify that the headphones have
a separate volume control.
Operable with some Determine whether there are any connection points for
hearing loss
external devices. Verify that existing connection points for
external audio processing devices have industry standard
connectors.
Operable with some Verify that auditory information is presented continuously or
hearing loss
periodically until the desired message is confirmed or acted
upon by testing device response when messages are not
Operable with limited acted upon immediately. If spoken messages do not
cognitive skills or
automatically repeat, verify that the hardware has a
language facility
mechanism for requesting their repetition.
Operable with some Test sound quality throughout the range of volume and
hearing loss
inspect the coupling (speaker output) between the signal
source and the user in order to verify that sound is
intelligible at all volumes. Verify that hardware volume can
be adjusted (dynamic range is 18-25 dB) (GT comment and that the volume indicator is visual and easily located).
Verify that at least one mode of operation enhances
auditory functioning via increased amplification or increased
signal-to-noise ratio or combination.
Operable with all
Modify volume settings. Turn off main power and restart
disability types
the machine. Review volume settings after restarting the
hardware and verify that volume settings are maintained
after the machine has been shut down (for items intended
for individual use).
Operable with some Inspect the impact of hardware noise on the acquisition of
hearing loss
auditory information and verify that it has been minimized.
Operable with some If a headphone is provided, inspect each side of the device
hearing loss
and verify that a headphone jack is provided and efficiently
located (GT comment - a 9-mm miniature plug-in jack is
recommended).
Operable with some If a headphone jack is not possible, verify that sound
hearing loss
sources are placed in front of the device and away from
loud mechanisms.
Operable with some Identify when alerting tones occur. Verify that alerting tones
hearing loss
contrast with expected environmental sounds.
Operable with some
hearing loss
Operable with some
hearing loss
Operable with all
disability types
Identify all types of audio output and measure pitch for
each. If pitch cannot be selected by the user, verify that
high pitch sounds ( > 4,500 Hz) are not used.
Verify that a gain adjustable up to a minimum of 20 dB is
provided for transmitted voice signals, with incremental
volume control of at least one intermediate step of 12 dB of
gain.
Verify that microphones have a muting function.
201
Guideline Source
Guidance
EITAAC
5.2.2.3
Section 255
1193.51(b)
Section 255
1193.43(e)(2)(d) - Advisory
Guidance
Vanderheiden, 1997
Section 255
1193.43(e)(2)(a) - Advisory
Guidance
EITAAC
5.2.1.5.4.2
Vanderheiden, 1997
Mercinelli 2.3
Vanderheiden, 1997
Section 255
1193.43(e)(2)(f) - Advisory
Guidance
Section 255
1193.43(e)(2)(e) - Advisory
Guidance
Section 255
1193.43(e)(2)(b) - Advisory
Guidance
Mercinelli 2.3
Vanderheiden, 1997
Section 508
1194.23(f)
EITAAC
5.2.1.5.3
Mercinelli 2.8
Disability
Operable with all
disability types
Operable with all
disability types
Operable without
speech
Operable without
speech
Evaluator Instructions
Test microphone sensitivity and verify that it is adjustable
within a range of ± 9-10 dB.
Inspect the mounting of microphones and verify that the
effects of the echo, sound, and reverberation from the
expected usage environment have been minimized.
Verify that at least one mode of operation and information
retrieval that does not require speech is provided; or,
alternatively, that support for assistive technology used by
people with speech disabilities is provided.
Verify that input options do not require speech and that
where speech is an input option alternatives are provided
(e.g., keyboard access).
Operable with limited
cognitive skills or
language facility
Operable with some Where softkeys (physical keys with variable labels) are
vision loss
used, inspect each softkey label and verify that each is selfexplanatory and does not use abbreviations.
Operable with limited
cognitive skills or
language facility
Operable with
Where softkeys (physical keys with variable labels) are
complete blindness
used, inspect each softkey and verify that each is used
consistently across applications.
Operable with limited
cognitive skills or
language facility
Operable with some Where softkeys (physical keys with variable labels) are
vision loss
used, inspect each softkey and its label to verify that
softkey positions correspond to softkey label positions.
Operable with limited
cognitive skills or
language facility
Operable with some Where softkeys (physical keys with variable labels) are
vision loss
used, inspect each phase of the display and verify that
softkey labels always appear at the same position on the
Operable with limited display.
cognitive skills or
language facility
Operable with all
Identify long command sequences. Determine if they can
disability types
be programmed. Verify that long command sequences can
be programmed with a short code (or with a few, simple
steps).
Operable with
Identify all controls and their sensory modes. Inspect all
complete blindness
controls and verify that there is multisensory indication of
the separate divisions, positions, and levels of each, and of
Operable with some each control’s status. Verify that rotational or linear stops
vision loss
and tactile or audio detents are provided.
202
Guideline Source
Mercinelli 2.8
Mercinelli 2.8
Section 508
1194.31(e)
Section 255
1193.41(h)
EITAAC
5.2.1.8.1
Section 255
1193.41(h)
Mercinelli 2.4
Mercinelli 2.4
Mercinelli 2.4
Mercinelli 2.4
Vanderheiden, 1997
Microsoft, 1999
Section 255
1193.41(a)(3)(f)
1193.41(a)(3)(g) - Advisory
Guidance
Disability
Evaluator Instructions
Operable with limited Test all system actions and verify that a progress, or “busy”
cognitive skills or
indicator is provided when the product cannot take further
language facility
input or when there is a delay before requested actions are
taken.
Operable with limited Inspect the wording of each output format and display to
cognitive skills or
verify that language is simple, and that no passive voice or
language facility
negative phrasing is used.
Operable with limited Inspect the system and identify any programmable keys or
cognitive skills or
the ability to modify default settings. Inspect the required
language facility
commands for common system functions and verify that
programmable function keys or system “default” modes are
provided for each.
Operable with limited Inspect the control space and verify that, where
cognitive skills or
appropriate, absolute reference controls (e.g., pointers) are
language facility
used instead of relative controls (e.g., unmarked knobs).
Operable with limited Inspect the control space and verify that, where
cognitive skills or
appropriate, moving pointers with stationary scales are
language facility
used.
Operable with limited Inspect the control space and verify that the number of
cognitive skills or
control choices (for a particular action key) and duallanguage facility
purpose controls are limited.
Operable with limited Inspect the control space and determine the controls
cognitive skills or
available at various layers. Verify that controls are layered
language facility
such that only the most frequent or necessary controls or
commands are visible unless requested.
Operable with limited Inspect the control space. Verify that controls are arranged
cognitive skills or
to indicate sequence of operation.
language facility
Operable with limited Inspect the control space and verify that common layouts or
cognitive skills or
patterns for controls are used (within the device).
language facility
Operable with limited Inspect the control space and verify that common colorcognitive skills or
coding conventions are provided in addition to textual or
language facility
graphic labeling.
Operable with limited Inspect system responses to all commands and identify any
cognitive skills or
lags. Verify that product lag or response times to
language facility
commands are minimized.
Operable with limited Inspect each setting control and verify that concrete (rather
cognitive skills or
than abstract) indications of product settings are used.
language facility
Operable with limited Inspect each screen layout and verify that they are simple,
cognitive skills or
and the user has the option to view one thing at a time.
language facility
Operable with limited Inspect each output of the display and verify that digital
cognitive skills or
readouts for product generated numbers are provided when
language facility
a numeric or precise value is important. Verify that dials or
bar graphs are provided when qualitative information is
more important.
Operable with limited Inspect each output format and display, including all button
cognitive skills or
labels, to verify that pictures or icons are used to
language facility
accompany words.
203
Guideline Source
Vanderheiden, 1997
Vanderheiden, 1997
Vanderheiden, 1997
Vanderheiden, 1997
Vanderheiden, 1997
Vanderheiden, 1997
Vanderheiden, 1997
Microsoft, 1999
Vanderheiden, 1997
Vanderheiden, 1997
Vanderheiden, 1997
Vanderheiden, 1997
Vanderheiden, 1997
Vanderheiden, 1997
Vanderheiden, 1997
Vanderheiden, 1997
Disability
Evaluator Instructions
Operable with limited Inspect each output format and display to identify any
cognitive skills or
important information and any grouped information.
language facility
Examine any coding techniques that are used. Verify that
key information and grouped information are highlighted
using attention-attracting and grouping techniques.
Operable with limited Inspect each output format and display and verify that
cognitive skills or
Arabic notation is used for numerals.
language facility
Operable with limited Inspect each aspect of the interface and verify that shape,
cognitive skills or
color, icons, and labels for controls sharing functions or
language facility
actions are standardized according to other products and
manufacturers. Verify that the use of images is consistent
throughout the application.
Operable with limited Identify actions requiring a sequence of operations. Inspect
cognitive skills or
each aspect of the interface and verify that memory cues or
language facility
simple operating instructions for required sequences of
action are provided. Test all command sequences, and
verify that an easy method for undoing or exiting out of
each is provided and apparent.
Operable with limited Identify all icons and graphical objects. Try to identify the
cognitive skills or
metaphor associated with each. Inspect all screen object
language facility
controls and verify that each is represented by common,
recognizable metaphors.
Operable with limited Inspect all labels and verify that each is placed on or
cognitive skills or
immediately adjacent to their corresponding control.
language facility
Identify labels not placed directly on a control. Inspect all
labels and verify that when one must be placed adjacent to
a control, the connection between the label and
corresponding control is made apparent.
Operable with limited Identify and inspect all labels and verify that simple concise
cognitive skills or
language is used for each while abbreviations are avoided.
language facility
Operable with limited Identify any aurally presented information and verify that
cognitive skills or
audio presentations are short, and that key information is
language facility
provided at the end. Verify that important information is
provided at the beginning of written text.
Operable with limited Identify any aurally presented information and verify that
cognitive skills or
attention-getting sounds or words are used before the audio
language facility
presentation of information.
Operable with limited Verify that there is automatic, timed shut-off for devices that
cognitive skills or
present a hazard if left on.
language facility
Operable with limited Identify any use of lists. Test all lists and verify that clear
cognitive skills or
feedback indicates the end of lists.
language facility
Operable with limited For all controls, verify that controls and keys are operable
manual dexterity
with one hand; and do not require tight grasping, pinching,
or twisting of the wrist. Measure the force required to
Operable with limited activate controls. Verify that the force required to activate
reach and strength
controls and keys, insert and retrieve items (cards,
connectors, drawers) is a maximum of 5 lb (22.2 N).
204
Guideline Source
Vanderheiden, 1997
Vanderheiden, 1997
Microsoft, 1999
Vanderheiden, 1997
EITAAC
5.3.2.5
Section 255
1193.41(i)(2)(e) - Advisory
Guidance
Vanderheiden, 1997
Mercinelli 2.5
Vanderheiden, 1997
Section 255
1193.41(i)(2)(f) - Advisory
Guidance
Vanderheiden, 1997
Vanderheiden, 1997
Vanderheiden, 1997
Microsoft, 1999
Section 508
1194.23(k)(2)
1194.25(c)
1194.26(a)
1194.26(b)
Disability
Evaluator Instructions
Operable with limited For all controls, identify whether key repeat is supported.
manual dexterity
Measure the delay for key repeat. Verify that if key repeat
is supported, the delay before repeat is adjustable to at
least 2 seconds.
Operable with limited Verify that at least one mode of operation and information
manual dexterity
retrieval does not require fine motor control or simultaneous
actions. Verify that at least one mode of operation and
Operable with limited information retrieval is available and operable with limited
reach and strength
reach and strength.
Guideline Source
Vanderheiden, 1997
Section 508
1194.23(k)(3)
1194.25(c)
1194.26(a)
1194.26(b)
Vanderheiden, 1997
Section 508
1194.31(f)
Section 255
1193.41(e)
1193.41(f)
EITAAC
5.2.1.6.1
HFDS
8.18.2.1
Section 255
Operable with limited Identify any actions that require simultaneous button
manual dexterity
presses. Verify that where two buttons must be depressed 1193.41(e)(2)(d) - Advisory
simultaneously, an option is provided to allow them to be
Guidance
activated sequentially, or an alternative method of control is
provided.
Vanderheiden, 1997
Microsoft, 1999
Section 255
Operable with
Determine whether optional voice control and speech
complete blindness
output are provided. If optional voice is available, verify that 1193.41(a)(3)(h) - Advisory
a query mode is also available which allows the user to
Guidance
determine (through speech output) the function or state of
the control without activating it.
Operable with limited Inspect insertable objects and verify that objects to be
Vanderheiden, 1997
manual dexterity
inserted are rugged and able to take rough handling
(nothing is apparently delicate).
Operable with limited Verify that latches are operable with a closed fist.
Vanderheiden, 1997
manual dexterity
Operable with limited Verify that knobs are not required for opening the product. Vanderheiden, 1997
manual dexterity
Section 255
Operable with limited Inspect each control mechanism. Verify that controls
manual dexterity
requiring simultaneous activation of two or more buttons or 1193.41(e)(2)(f) - Advisory
latches are avoided. Also verify that small controls and
Guidance
controls requiring rotation of the wrist or pinching and
twisting are avoided.
Section 255
Operable with limited Use a pen or eraser tip to activate controls. Verify that
manual dexterity
controls are operable/compatible with prosthetics, and do
1193.51(c)
not require human touch.
EITAAC
5.2.1.14
Operable with limited Verify that cards, external connectors, and drawers can be Mercinelli 2.4
manual dexterity
inserted and retrieved with a single hand.
205
Disability
Evaluator Instructions
Operable with limited Verify that an optional mode is provided where buttons
manual dexterity
must be depressed for a long period of time before input is
accepted (to help separate inadvertent keypresses from
desired activation), or that the delay before acceptance of
input can be preset and adjusted.
Operable with limited Verify that guard bars are available between or near
manual dexterity
buttons to help prevent accidental activation.
Operable with
complete blindness
Verify that a standard connection point for applicable
assistive input devices (e.g., screen keyboards, predictive
dictionaries, and speech recognition technologies) is
Operable with limited provided.
manual dexterity
Operable with limited Inspect the required actions to execute command
cognitive skills or
sequences and verify that required command sequences
language facility
are simple, requiring minimal steps, or can be programmed
with a short code.
Operable with limited Inspect the control space to verify that controls are spaced,
manual dexterity
positioned, and sized to facilitate manipulation.
Guideline Source
Section 255
1193.41(e)(2)(c) - Advisory
Guidance
Vanderheiden, 1997
Section 255
1193.41(e)(2)(b) - Advisory
Guidance
Vanderheiden, 1997
Microsoft, 1999
Vanderheiden, 1997
Section 255
1193.41(e)(2)(a) - Advisory
Guidance
Section 255
Operable with limited Inspect each key or button to verify that concave and/or
manual dexterity
non-slip buttons (rubbery texture is preferred by most) have 1193.41(e)(2)(g) - Advisory
been used, or that a ridge is provided around flat keypad
Guidance
buttons. Verify that controls are shaped to minimize the
need for pinching or bending the wrist or body, and can be HFDS
operated using the side of the hand, an elbow, or a pencil. 6.4.1.7
Vanderheiden, 1997
Vanderheiden, 1997
Operable with limited Inspect each insertable object and verify that it has a highmanual dexterity
friction surface (to ease the grip necessary to maintain hold
of the object).
Operable with limited If controls require fine motor control, verify that alternative Vanderheiden, 1997
manual dexterity
methods of control are provided.
Microsoft, 1999
Section 255
Operable with limited If cards, connectors, or drawers must be inserted, verify
manual dexterity
that a bevel is provided around the slot/connection area,
1193.41(e)(2)(h) - Advisory
and/or that the slot/connector is located on the front and
Guidance
near a ledge or open space for easy insertion/connection.
Operable with limited If a touchscreen is used, measure each object to verify that Mercinelli 2.5
manual dexterity
it is 2.6 sq cm or larger, and that on screen “keys” are 2.27
sq cm or larger. Also verify that on-screen “keyboard” keys
are separated by +0.41 to 0.54 cm.
Operable with limited If a touchscreen is used, inspect each key to verify that last Mercinelli 2.5
manual dexterity
key selection algorithms (the system accepts selection from
the last valid key touched prior to finger raising; if finger is
raised outside a screen “sensible” area no selection should
be made) are used.
Operable with
If a flat membrane keypad cannot be avoided, verify that a Vanderheiden, 1997
complete blindness
ridge around each button has been provided (thickness
changes of at least 1/32” the most readily detectable).
Operable with limited Verify that tilt angle for screen typing is between 30-45°.
Mercinelli 2.5
206
Disability
manual dexterity
Operable with limited
manual dexterity
Operable with limited
manual dexterity
Operable with limited
manual dexterity
Evaluator Instructions
Verify that keyboards are adjustable from the horizontal (015°).
Identify controls and verify that they can be operated with
either the right or the left hand.
Identify all controls and verify that there are no obstructions
that would interfere with a user’s ability to manipulate a
control.
Operable with limited Determine how all controls function and verify that no
manual dexterity
control requires the user to continuously hold it down in
order to activate it unless safety requirements dictate
otherwise.
Operable with limited Identify all controls and determine how they can be
manual dexterity
manipulated. Verify that controls are designed to permit
users great flexibility in how the control is manipulated,
whether by using the fingers, the full hand, or both hands.
Operable from a
When the obstruction projects 20 to 25 inches (510 mm to
seated position
635 mm), verify that the maximum high forward reach is 44
inches (1120 mm) (compliant with American Disabilities Act
Operable with limited Accessibility Guidelines).
strength and reach
Guideline Source
Vanderheiden, 1997
HFDS
6.4.1.6
HFDS
6.4.1.12
HFDS
6.4.1.13
HFDS
6.4.1.14
Section 255
1193.41(f)(2)(f) - Advisory
Guidance
EITAAC
5.2.1.16
HFDS
6.4.1.15
Section 255
Operable from a
When the obstruction is less than 20 inches (510 mm)
seated position
deep, verify that the maximum high forward reach is 48
1193.41(f)(2)(f) - Advisory
inches (1220 mm) (compliant with American Disabilities Act Guidance
Operable with limited Accessibility Guidelines).
EITAAC
strength and reach
5.2.1.16
Operable with limited Verify that the requirement for constant, uninterrupted
manual dexterity
actions is minimized by investigating the required actions
for each control.
Operable with limited
strength and reach
Operable from a
Verify that the maximum level forward reach over an
seated position
obstruction with knee space below is 25 inches (635 mm)
(compliant with American Disabilities Act Accessibility
Operable with limited Guidelines).
strength and reach
HFDS
6.4.1.15
Vanderheiden, 1997
Section 255
1193.41(f)(2)(f) - Advisory
Guidance
EITAAC
5.2.1.16
HFDS
6.4.1.15
Vanderheiden, 1997
Operable with limited Verify that the manipulation of printouts by “reaching and
strength and reach
grasping” aids is facilitated by product design.
Operable with limited Verify that the force required to operate mechanical controls Section 255
207
Disability
strength and reach
Operable from a
seated position
Evaluator Instructions
is adjustable or minimized, and that the need for sustained
pressure or activity is minimized.
Verify that an optional remote control is provided such that
the controls can be positioned optimally for each individual.
Operable with limited
strength and reach
Guideline Source
1193.41(f)(2)(d) - Advisory
Guidance
Section 255
1193.41(f)(2)(c) - Advisory
Guidance
HFDS
6.4.1.17
Vanderheiden, 1997
Operable with limited Determine actions required to insert and remove objects.
manual dexterity
Verify that objects can be inserted and removed with
minimal user reach and dexterity by inspecting the insertion
Operable with limited and removal of each object.
strength and reach
Operable from a
Verify that multiple displays or auditory output are provided Vanderheiden, 1997
seated position
when information cannot be within reach of those who are
small or in a wheelchair or other personal mobility device.
Operable from a
Verify that important labels or instructions are placed on the Vanderheiden, 1997
seated position
front or other easily accessible side of large or stationary
HFDS
devices.
6.4.1.27
Operable with limited Verify, by attempting each operation with a single hand, that Microsoft, 1999
strength and reach
frequently performed control operations do not require long
reaches by people using one hand.
Operable with limited Verify that devices with covers or lids are hinged, have
Vanderheiden, 1997
strength and reach
sliding covers, or are electronically operated. Verify that
lids, covers, and other loose objects are hinged or tethered
with a cord or wire.
Operable with limited Verify that device doors with open handles, levers, or
Vanderheiden, 1997
manual dexterity
spring-loaded doors are used.
Operable with limited Verify that force requirements are minimized or that force
Vanderheiden, 1997
strength and reach
required for mechanical controls can be adjusted.
Operable from a
Verify that controls and printed output are within easy reach EITAAC
seated position
of those who are small or in a wheelchair or other personal 5.2.1.16
mobility device, and a required change in body position is
minimized: Accessible forward reach is between 15”and 48” HFDS
from the floor. Accessible side reach is between 9” and 54” 6.4.1.15
from the floor.
Vanderheiden, 1997
Operable with limited Verify that bearings for drawers or heavy objects that must Vanderheiden, 1997
strength and reach
be moved are provided.
Operable with limited Identify all controls that will be used frequently. Verify that Section 255
strength and reach
they are placed in positions that are most easily reached
1193.41(f)(2)(e) - Advisory
with the minimum change of body position and that
Guidance
arm/wrist rests or supports are provided near controls.
Alternatively, verify that short cuts are available to minimize HFDS
the number of actions needed to perform a given function. 6.4.1.16
Operable with limited Verify that ample ejection distance of objects (e.g.,
manual dexterity
printouts) facilitates easy gripping and removal
(recommended distance is 1 inch but 2 inches is preferred).
208
Vanderheiden, 1997
Vanderheiden, 1997
Disability
Operable from a
seated position
Evaluator Instructions
Inspect each receptacle and verify that object receptacles
can be repositioned or re-angled to be more reachable.
Operable with limited
strength and reach
Operable from a
Verify that controls are within easy reach of those who are
seated position
small or in a wheelchair or other personal mobility device,
and a required change in body position is minimized: If the
Operable with limited side reach is over an obstruction with a depth of 24 inches
strength and reach
(610 mm), verify that the maximum height of the obstruction
is 34 inches (865 mm) and that the maximum high side
reach over the obstruction is 46 inches (1170) (compliant
with American Disabilities Act Accessibility Guidelines).
Operable from a
seated position
Verify that controls are within easy reach of those who are
small or in a wheelchair or other personal mobility device,
and a required change in body position is minimized: If the
Operable with limited clear floor space only allows forward approach to the
strength and reach
product, verify that the maximum high forward reach
(height) allowed is 48 in (1220 mm) (compliant with
American Disabilities Act Accessibility Guidelines).
Guideline Source
Vanderheiden, 1997
Section 255
1193.41(f)(2)(f) - Advisory
Guidance
EITAAC
5.2.1.16
HFDS
6.4.1.15
Section 255
1193.41(f)(2)(f) - Advisory
Guidance
EITAAC
5.2.1.16
HFDS
6.4.1.15
Operable from a
seated position
Verify that controls are within easy reach of those who are
small or in a wheelchair or other personal mobility device,
and a required change in body position is minimized: If the
Operable with limited clear floor space only allows forward approach to the
strength and reach
product, verify that the minimum low forward reach is 15 in
(380 mm) (compliant with American Disabilities Act
Accessibility Guidelines).
Vanderheiden, 1997
Section 255
1193.41(f)(2)(f) - Advisory
Guidance
EITAAC
5.2.1.16
HFDS
6.4.1.15
Operable from a
seated position
Verify that controls are within easy reach of those who are
small or in a wheelchair or other personal mobility device,
and a required change in body position is minimized: If the
Operable with limited clear floor space allows parallel approach by a person in a
strength and reach
wheelchair, verify that the maximum high side reach
allowed is 54 in (1370 mm) and the low side reach is no
less than 9 in (230 mm) above the floor (compliant with
American Disabilities Act Accessibility Guidelines).
Operable with limited Determine the type of grasp required for each knob. As
manual dexterity
appropriate, measure the height, diameter, and length of
each knob. If it is a finger tip grasp, verify that the height of
the knob is no less than 13 mm (0.5 in) and no more than
25 mm (1.0 in). The diameter should be a minimum of 10
mm (0.4 in) and a maximum of 100 mm (4.0 in). If the knob
209
Vanderheiden, 1997
Section 255
1193.41(f)(2)(f) - Advisory
Guidance
EITAAC
5.2.1.16
HFDS
6.4.1.15
Vanderheiden, 1997
HFDS
6.1.5.4.1
Disability
Operable with limited
manual dexterity
Operable with limited
manual dexterity
Operable with limited
strength and reach
Operable with limited
strength and reach
Operable with limited
manual dexterity
Operable with limited
strength and reach
Operable with some
vision loss
Operable with limited
cognitive skills or
language facility
Evaluator Instructions
requires the thumb and forefinger encircled, verify that the
diameter of the knob is no less than 25 mm (1.0 in) and no
more than 75 mm (3.0 in). If the knob uses palm grasp,
verify that the diameter is no less than 38 mm (1.5 in) and
no more than 75 mm (3.0 in). The length should be a
minimum of 75 mm (3.0 in).
Determine if there are adjacent knobs. Verify that
separation between adjacent edges of knobs is as follows:
For one handed operation, the minimum is 25 mm (1.0 in)
and the optimum is 50 mm (2.0 in). When 2 hands are
required simultaneously, the minimum separation should be
50 mm (2.0 in) and the optimum is 125 mm (5.0 in).
Determine the type of grasp required for each lever. If the
lever uses finger grasp, verify that the minimum diameter is
13 mm (0.5 in) and the maximum is 38 mm (1.5 in). If hand
grasp is required, verify that the minimum diameter is 38
mm (1.5 in) and the maximum is 75 mm (3.0 in).
Determine whether the motion of the lever is forward or
lateral. If forward, verify that resistance for one handed
operation is a minimum of 9 N (2.0 lb) and a maximum of
135 N (30.0 lb). For two handed operation, verify that
resistance is a minimum of 9 N (2.0 lb) and a maximum of
220 N (50.0 lb). For lateral motion with one handed
operation, verify that the resistance is a minimum of 9 N
(2.0 lb) and a maximum of 90 N (20.0 lb). For lateral
motion with two handed operation, verify that the minimum
resistance is 9 N (2.0 lb) and the maximum 135 N (30.0 lb).
Determine whether the lever requires forward or lateral
motion and measure the displacement. If the lever requires
forward motion, verify that the maximum displacement is
360 mm (14.0 in). If the lever requires lateral motion, verify
that the minimum displacement is 50 mm (2.0 in) and the
maximum is 970 mm (38.0 in) (preferred is 100 mm (4.0
in)).
Measure separation between adjacent levers. Verify that
for one handed operation, the minimum separation is 50
mm (3.0 in) (preferred is 100 mm (5.0 in)). For two handed
simultaneous operation, verify that the minimum separation
is 75 mm (3.0 in) (preferred is 125 mm (5.0 in).
Identify all levers and determine whether they are to be
used for fine or continuous adjustments. Verify that when a
lever will be used to make fine or continuous adjustments, a
support for the appropriate limb is provided as follows: a.
For large hand movements, a support for the elbow.; b. For
small hand movements, a support for the forearm; c. For
finger movements, a support for the wrist.
Determine if animation is displayed. Verify that the
information is displayable in at least one non-animated
presentation mode at the option of the user. Options
include freezing the text, making it scrollable, or providing it
in an alternate format that does not move.
210
Guideline Source
HFDS
6.1.5.4.1
HFDS
6.1.5.15.1
HFDS
6.1.5.15.1
HFDS
6.1.5.15.1
HFDS
6.1.5.15.1
HFDS
6.1.5.15.5
Section 508
1194.21(h)
1194.22(m)
Section 255
1193.43(c) - Advisory
Disability
Evaluator Instructions
Prevention of visually
induced seizures
Guideline Source
Guidance
EITAAC
5.2.1.7.2
Operable with some
vision loss
Identify any use of color coding. Verify that color coding is
not used as the only means of conveying information,
indicating an action, prompting a response, or
Operable with little or distinguishing a visual element.
no color perception
HFDS
8.18.1.7
Section 508
1194.21(i)
1194.22(m)
1194.25(g)
EITAAC
5.3.2.8
5.2.1.3
Operable with some
vision loss
Operable with some
vision loss
Verify that the information density (the amount of
information per unit area) of a screen is minimized,
meaning that only information that is essential to a user at
any given time is presented.
Inspect the screens/web site pages and verify that mixed
case is used for text and that standard capitalization rules
are used.
HFDS
8.6.2.1.5
HFDS
8.1.1.2
HFDS
8.2.5.8.1
Vanderheiden, 1997
Section 255
Operable with limited Verify that there is at least one mode that minimizes the
cognitive skills or
cognitive, memory, language, and learning skills required of 1193.41(i)
language facility
the user.
EITAAC
5.2.1.9.1
5.2.1.10.1
211