Usability with Project
Lecture 5 – 23/09/09
© Simeon Keates 2009
Friday’s Exercise – part 1
 Work as a group
 Write a script (task analysis) for how you envisage each of your
personas would use your site
 Try to follow that script using your site
 Log any problems you encounter
 Then try another group’s site (more if you have time)
 Make any changes to your site based on your evaluations
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Heuristics as a
design approach
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Setting the scene
 “Rehabilitation Robotics in Europe” c.1997
 EU funded many projects under TIDE initiative
 LOTS of money!!!
 Projects generally major disasters
 Let’s see why…
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An example – The EPI-RAID robot
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EPI-RAID failed because…
 No in-built market to sell to
• Had to sell on its own merits
 Too expensive
• (~5000000DKK) Needed a user-centred design approach!
 Overtaken by new technology
• Internet
 Not enough consideration of what it was to be used for
• Too much focus on the technology
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Question
Can we use Nielsen’s heuristic in the design process?
 i.e. not just for post-hoc testing
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Reminder: The fundamental stages of design
 STAGE 1 - define the problem
user wants/needs
system requirements
 STAGE 2 - develop a solution
develop a usable system for “all” users
 STAGE 3 - evaluate the solution
verify/validate for all users
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The fundamentals of interaction
 Card, Moran and Newell (1983 – “The Psychology of Human-Computer
Interaction”) proposed that actions could be described by:
Time taken = xp + yc + zm
where p = time for one perceptual cycle
c = time for one cognitive cycle
m = time for one motor function
x, y & z are integers
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Putting heuristics into the design process
1
 STAGE 1 - Problem specification
LEVEL 1
 STAGE 2a - Visibility of system status
LEVEL 2
• PERCEPTION
2
 STAGE 2b - Match between system and real world
LEVEL 3
• COGNITION
 STAGE 2c - User freedom and control
LEVEL 4
• MOTOR FUNCTION
3
 STAGE 3 - Evaluation/verification
LEVEL 5
Also known as the 5-level model
See Keates and Clarkson “Countering design exclusion”
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Diagrammatically…
From: Keates & Clarkson
“Countering design exclusion”
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The IRVIS (Interactive Robotic Visual Inspection
System) prototype
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Questions of interest
 Question 1: Is the robot under-specified or fundamentally “wrong”?
 Question 2: Can we make it usable?
 Question 3: Can we make it accessible?
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Level 1 - Problem requirements
 AIM 1: What are the system requirements?
 AIM 2: Why did the original interface fail?
 ASSESSMENT: Verify problem definition
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Level 1 – Understanding the system requirements
product
objectives
potential
users
specific
requirements
 What are the system requirements?
• Understand manual process
• User observations
 Why did the original interface fail?
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The original interface
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Level 1 - Problem specification (cont.)
 Inspection process requires:
•
•
•
•
•
Translation
Rotation
Tilting
Zooming
Focusing
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Developing a solution: the “Variable Fidelity Prototype”
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Level 2 - Output to user – “Visibility of system status”
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Level 3 - User mental model – “Match between system
and real world”
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Level 4 - Input from user – “User freedom and control”
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Level 5 – Verifying functional and usability attributes
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Level 5 - Social attributes
 The design of a new interface has shown significantly
increased usability
 Qualitative user feedback extremely favourable
 The final interface also showed improved usability for ablebodied users
 Costly robot re-build avoided
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Features of the 5-level model
 Iterative approach, with user trials and evaluation at each level
 Addresses each stage of the interaction process explicitly
 Guidelines can be incorporated where applicable
 Clear focus on usability
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Improving the 5-level model…
 Will be seen a little later…
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Summary
 Usability and design are closely intertwined
 Usability needs to consider design perspectives
 Usability methods used need to complement design process and stage
of development lifecycle
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Introducing “inclusive design”
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The need for inclusive design - a “typical” user
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The need for inclusive design - the bigger picture
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What is a good/inclusive interface?
 Acceptable by the intended user group
Need to define:
 What is the intended user group?
 What is acceptable?
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Who are the intended users?
Typical user stereotypes
 The “disabled”
 The “elderly”
 The “person in the street”
 The “customer”
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Designing inclusively = design for the disabled (?)
 Need to adopt inclusive design arises because user capabilities ≠
product demands
 Thus users with limited or impaired capabilities need a more accessible
version to be designed
 User group most commonly (stereotypically) associated with limited or
impaired capabilities is people with disabilities
 Ergo – designing inclusively is really designing for the disabled
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Inclusive design philosophies
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TOP DOWN
Least capable
BOTTOM UP
Least capable
Most capable
Most capable
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Examples of the different approaches
TOP DOWN
BOTTOM UP
AN Other Mouse
>€1500
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<€100
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Approaches to “designing for the widest possible range
of users”
 Universal Design
 Design for All
 Universal Access
 Inclusive Design
 Countering Design Exclusion
 Design for disability
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Universal Design
 For a long time the most famous “inclusive design” approach
 Very popular in Japan and USA
 Strong association with architectural design
• Buildings access
 Not big in Europe
• “Guiding principles” seen as too rigid and too deeply associated with its US
heritage
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The 7 guiding principles of Universal Design
 1 - Equitable use
• The design must be useful and marketable to people with diverse abilities
 2 - Flexibility in use
• The design accommodates a wide range of individual preferences and
abilities
 3 - Simple and intuitive
• Use of the design is easy to understand, regardless of the user’s experience,
knowledge, language skills or current concentration level
 4 - Perceptible information
• The design communicates necessary information effectively to the user,
regardless of the ambient conditions or the user’s sensory abilities
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The 7 guiding principles of Universal Design
 5 – Tolerance for error
• The design minimises hazards and the adverse consequences of accidental
or unintended actions
 6 – Low physical effort
• The design can be used efficiently and comfortably and with a minimum of
fatigue
 7 – Size and space and approach for use
• Appropriate size and space is provided for approach, reach, manipulation
and use regardless of user’s body size, posture or mobility
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Other approaches to designing for the most possible
users
 Design for All
• An older approach, very popular at one time
 Inclusive design
• Popular in Europe
• More flexible approach than Universal Design
 Universal Access
• “Inclusive design for HCI”
 Countering design exclusion
• Developed by Keates and Clarkson (see book of same name)
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Design for All(?)
 Synonymous with “one product for all” (note – incorrectly)
• Not really a feasible goal (see first lecture)
 EU eEurope initiative defines DfA as:
• “…designing mainstream products and services to be accessible by as
broad a range of users as possible.”
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Defining “inclusive design” (source: Keates “Designing
for accessibility”)
 UK Department of Trade and Industry:
• Inclusive design is a process whereby “…designers ensure that their
products and services address the needs of the widest possible audience.”
 RSA (Royal Society for the Encouragement of Arts, Manufacture and
Commerce):
• Inclusive design is “… about ensuring that environments, products, services
and interfaces work for people of all ages and abilities.”
 UK Design Council:
• “Inclusive design is not a new genre of design, nor a separate specialism,
but an approach to design in general and an element of business strategy
that seeks to ensure that mainstream products, services and environments
are accessible to the largest number of people.”
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Countering design exclusion (CDE)
 Defined in BS7000 Part 6:
• Design exclusion is the “…inability to use a product, service or facility, most
commonly because the needs of people who experience motor, sensory and
cognitive impairments have not been taken into account during the design
process.”
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CDE philosophy
 If you can identify who cannot use the product and why, then you know
what to focus on fixing
 More practical approach than “design for a wide variety of users (but
we’re not going to tell you who and how many) in a wide variety of
circumstances (ditto)”
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What is exclusion?
Whole
population
Increasing
motion
capability
Excluded
population
Included
population
Increasing
sensory
capability
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Increasing
cognitive
capability
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Where does exclusion come from?
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Where does design exclusion come from?
“Designers design for themselves”
Examples to follow…
Design trade-offs…
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Limits to inclusion - trade-offs
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An example compromise
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How are people excluded?
People are excluded based on their capabilities (DFS)
MOTION •
•
locomotion
•
reach and stretch
•
dexterity
•
intellectual functioning
hearing
• vision
• communication
and the demands made by the product
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SENSORY
COGNITIVE
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Quantifying exclusion
 We will look at how to measure and report exclusion in later lectures
 You will see examples in the reading material for this week
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Prevalence…
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Where to look for prevalence data
 The charities
• RNIB, NFB, AFB, RNID, etc.
 Lots of really useful information and data
• e.g. http://www.rnib.org.uk/xpedio/groups/public/documents/publicwebsite/public_researchstats.hcsp
 Great info about causes and symptoms
 Question: Are these unbiased sources of data?
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Charities and prevalence data
 Difficult to tell how unbiased data is
 Best sites cite independent studies
 Others mention figures with no (or dubious) attributions
 Need to treat such data cautiously
 Better to rely on “official” sources, e.g. government bodies
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Defining “disability” - WHO
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Prevalence of “disability” in US (source: US Census
Bureau 1999-2004 American Community Survey)
Respondents: 16+
% of Total
220,073,798
Margin
of Error
±129,242
With any disability
16.0
±0.1
With a sensory disability
4.7
±0.1
With a physical disability
10.6
±0.1
With a mental disability
5.2
±0.1
With a self-care disability
3.1
±0.1
With a go-outside-home disability
4.9
±0.1
With an employment disability
5.6
±0.1
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Multiple capability losses in US (source: US Census
Bureau 1999-2004 American Community Survey)
Respondents: 5+
% of Total
264,965,834
Margin
of Error
±65,181
Without any disability
85.7
±0.1
With one type of disability
6.7
±0.1
With 2 or more types of disabilities
7.6
±0.1
We will look at the implications of multiple impairments later…
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UK Disability Follow-Up Survey
 Follow-up to 1996/7 Family Resources Survey
 7500 respondents
 13 separate capabilities identified as important to independent living
We will
look a lot more closely
 7 relevant for product
design:
•
•
•
•
•
•
•
Locomotion
Reach and stretch
Dexterity
Seeing
Hearing
Communication
Intellectual Functioning
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at this next week
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Mapping to interaction models
 Motor = locomotion, reach & stretch, dexterity
 Sensory = seeing, hearing
 Cognitive = communication, intellectual functioning
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UK Disability Follow-Up Survey (Grundy et al, 1999)
Loss of capability
No. of GB 16+
population
% of GB 16+
population
Motor
6 710 000
14.3%
Sensory
3 979 000
8.5%
Cognitive
2 622 000
5.6%
Motor only
2 915 000
6.2%
Sensory only
771 000
1.6%
Cognitive only
431 000
0.9%
1 819 000
3.9%
Sensory and cognitive only
213 000
0.5%
Cognitive and motor only
801 000
1.7%
Motor, sensory and cognitive
1 175 000
2.5%
Motor, sensory or cognitive
8 126 000
17.3%
Motor and sensory only
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Disability Follow-up summary
 8,582,200 adults in GB have a disability
• 17% of the total population (1 in 6)
Of these:
 34% had mild impairments
 45% had moderate impairments
 21% percent had severe impairments
 49% had more than one impairment type
 48% of disabled population is over 65
 29% of disabled population is over 75
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Importance of ageing
 Population is getting older
60
70 +
50
UK population
(millions)
50 - 69
40
30 - 49
30
20
15 - 29
10
0
0 - 14
1901
1931
1961
1991
2021
Year
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It’s not just blindness
 Traditionally most “accessibility” approaches for HCI have focused on
blindness
Reasons:
 Very “visible” difficulty
 Very easy to simulate
• Switch off the monitor
 Very effective lobbying group
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WCAG 1.0 and 2.0
Look through the WCAG guidelines:
 How many address vision issues (specifically blindness)?
Answer: Most
 How many address motor issues?
Answer: Some
 How many address cognitive issues?
Answer: Few
 How many address hearing issues?
Answer: Few
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Problem with focus on blindness
From DFS:
 1.93 million people have vision impairment
 Only 20% of those are “blind”
• Need screen readers, etc.
 80% are “low vision”
• Need screen magnification
 c.f. 2.9 million people with hearing impairments
 …and 6.7 million with motor impairments
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Sensory impairments – Classes of impairment
 Vision
• Blindness – cannot see “at all”
• Low vision – cannot see well
• Colour blindness – cannot see all of the colour spectrum
 Hearing/auditory
• Deafness – cannot hear “at all”
• Low hearing – cannot hear well
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Cognitive impairments – Classes of impairment
 Poor long-term memory
 Poor short-term memory
 Dementia – e.g. Alzheimer’s
 Language “deficits” – e.g. below chronological reading age
 Reading difficulties – e.g. dyslexia
 Behavioural/attentional difficulties – e.g. ADD, ADHD
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Motor impairments – Classes of impairment
 Restricted range of motion
 Tremor
 Spasm
 Poor co-ordination
 Limited strength
 Poor fine movement
 Poor ballistic movement
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Exercise
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Exercise – part 1
 Each group will be assigned a type of website
•
•
•
•
•
•
•
Group 1 – car rental sites (e.g. Avis, hertz, alamo, budget)
Group 2 – airline flight booking sites (e.g. flysas, virginatlantic, ba, sterling)
Group 3 – travel insurance sites (e.g. columbusdirect)
Group 4 – luggage (e.g. tumi)
Group 5 – clothing (e.g. versace, lacoste)
Group 6 – news sites (e.g. CNN, BBC)
Group 7 – social networking sites (e.g. Facebook, Myspace)
 You must look at a minimum of 3 sites
 For each website, use CynthiaSays (http://www.contentquality.com/) to
examine the reported accessibility of each site (WCAG Priority 1, 2 & 3)
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Exercise – part 2
 Use Nielsen’s heuristics from last week’s exercises to estimate the
usability of each site
 Question: Is there any relationship (correlation) between the overall
usability and accessibility of the sites (as measured here)?
 Prepare a 5 minutes presentation for Friday morning with your answer
to the above question
 No report needed for this exercise!
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