Fun and Usable: Augmented Reality Instructions in a
Hospital Setting.
Susanna Nilsson
Björn Johansson
Department of Computer and Information Science
Linköping Univeristy, Sweden
+46 (0)13 28 26 90
Department of Computer and Information Science
Linköping University, Sweden
+46 (0) 13 28 24 25
susni@ida.liu.se
bjojo@ida.liu.se
ABSTRACT
The differences between Augmented Reality (AR) systems and
computer display based systems create a need for a different
approach than “traditional” HCI to the design and development of
AR systems. This paper presents theoretical and empirical work
which uses holistic approach compared to traditional guidelines in
human computer interaction. The paper includes a usability study
where AR was used for giving instructions to professional users in
a hospital. The theoretical stance of Cognitive Systems
Engineering is suggested as a possible approach to the design of
AR system. The analysis show that the users in the context of
medical care are positive towards AR systems as a technology and
as a tool for instructions. This indicates that AR technology may
become an accepted part of every day work in such a context.
use, the surrounding and the effect the system or interface may
have in this respect. Being contextually aware in designing an
interface means having a good perception of who the user is and
where and how the system can and should affect the user in her
tasks.
This article aims at discussing usability and user acceptance
aspects of an Augmented Reality (AR) system from a Cognitive
Systems Engineering (CSE) perspective. A case study of an AR
prototype tested by professional users is presented. The results
from the study are mainly intended as a basis for discussion of the
design of AR systems from a CSE perspective.
2. MIXED AND AUGMENTED REALITY
Usability, Augmented Reality, Mixed Reality. User Study,
Cognitive Systems Engineeering.
Mixed Reality (MR) is a collective name for the technologies
developed to merge real and virtual information. Milgram and
Kishino (1994) describe Mixed Reality as a virtual continuum
which illustrates the relation between Augmented Reality, virtual
reality (VR) and the stages in between [19]. VR are systems that
are totally immersive and allows the user to experience a more or
less complete virtual world, while AR only amplifies certain
features, or adds some virtual effects, to the world as it is
experienced by the user. Usually the virtual elements are
presented visually through a head mounted or a mobile display.
The focus in many MR definitions is ‘the merging of worlds’ but
MR is also defined as the technology used to accomplish this
merging of real and virtual worlds.
1. INTRODUCTION
2.1 Augmented Reality
Categories and Subject Descriptors
H.5.1 [Information Interfaces and Presentation, HCI]:
Multimedia Information systems – Artificial, augmented and
virtual realities.
General Terms
Design, Human Factors,
Keywords
When new technologies are introduced into a domain it may affect
the user and the task on both a practical and a social level. The
process of change requires knowledge, not only about the system
introduced but also about the domain. The technical system or
interface which is introduced should have as much positive effect
on the user and her/his work as possible, while at the same time
minimizing the negative effects of the system both for the user
and other individuals. Fundamental usability awareness implies
that the interface or system should not be harmful or confusing to
the user, but rather aid the user in her/his tasks. However,
traditional usability guidelines often do not include the context of
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Azuma (1997) mentions three criteria that have to be fulfilled for
a system to be classified as an AR system: they all combine the
real and the virtual, they are supposedly interactive in real time
(meaning that the user can interact with the system and get
response from it without delay), and they are registered and
aligned in three dimensions [1]. As an example, motion pictures
with advanced 3D effects might have elements of AR, but they are
not interactive so the do not qualify in the AR category.
AR applications can be found in diverse domains, such as
medicine [25], military applications [8, 9], entertainment and
infotainment [16], technical support and industry applications [3,
12, 30], distance operation [20] and geographical applications
[15]. One application area is as instructional tools; Tang [27]
describes an experimental evaluation of AR used in object
assembly; Zauner et al [30] describe how MR can be used as an
assembly instructor for furniture applications. The ARVIKA
project illustrated several different applications for development,
production and service [7]. A common application with AR is to
provide instructions on how to operate new or unfamiliar
equipment. The instructions given in an object assembly situation
may however be slightly different from instructions given on how
to operate and manage unfamiliar technical equipment.
Technically, there are two principally different solutions for
merging reality and virtuality in real time today – video seethrough and optic see-through [1, 2, 16]. Optic see-through is
where the user has a head mounted see-through optical display
which allows the user to see the real world as if through a glass
lens. The virtual information is then overlaid on the see-through
display. This technique causes some problems since the virtual
information has to compete with the surrounding light, which
places great demands on the display capabilities (it can be
compared with having to work with a computer screen in direct
sunlight). There are also some problems with placement of the
information in relation to the surroundings since the depth of the
display in this constellation is fixed whereas in reality objects are
perceived in different focal planes [8].
A way to overcome the problems with optic see-through is by
using a camera in front of the users’ eyes, and then projecting the
camera image on a small display in front of the users’ eyes [1, 8,
16]. The virtual images are added to the real image before it is
projected which solves the surrounding light problem as well as
gives control over where the virtual objects are placed (see figure
1).
Figure 1: Schematic view of a Video see-through AR
system [24].
This places other demands on the system, as the transferring of the
real image suffers from the lag determined by the camera image
update frequency. The lag can have effect on the user experience
of the system, such as simulator sickness. To conclude there is a
trade-off between the two different solutions and the choice of
solution is often determined by the available resources.
2.2 Augmented Reality and Usability
AR is a relatively new field, where technological possibilities are
the driving forces, meaning that little reflection is done regarding
the consequences of introducing such technology in actual
situations. The impact of the way AR is envisioned (optic seethrough and video see-through) has largely taken focus off the use
situation and instead lead to a focus on more basal aspects, such
as designing for avoiding motion sickness and increasing the
physical ergonomics of the technology. However, these areas are
merely aspects of the platform MR/AR, not the applications it is
supposed to carry and the situations in which they are supposed to
be used.
The field of AR differs from standard desktop applications in one
crucial respect; it is intended to be used as a mediator or amplifier
of human action, often in physical interaction with the
surroundings. Although this is valid for several other forms of
systems as well, AR is unique in the sense that it changes the
user’s perception of the world in which she/he acts, and thus
fundamentally affects the way the user behaves. This is also why
the need to study contextual effects of introducing AR systems
seems even more urgent to study. Usability methods used for AR
systems are mainly based on usability methods used for graphical
user interfaces, sometimes in combination with usability for VR
applications [8, 28]. This approach has some complications since
it is not based on the experiences from actual AR systems users in
actual contexts. Usability criteria and heuristics that are useful for
designing new AR systems tend to be general, broad criteria, such
as the ones Nielsen presented in his list of usability heuristics in
1993 [23]. Usability methods such as cognitive task design [11],
where the design approach is based on observations of how a user
completes a task in which the system or artifact is involved, also
have to deal with the so called ‘envisioned world problem’ [13,
29]. The ‘envisioned world’ problem states that even if a good
understanding of a task exists, the new design/tool will change the
task, rendering the first analysis invalid.
Designing systems based on heuristics developed for computer
based applications may be common practice in the MR/AR field,
but there are few examples of studies on how users actually
perceive the system in actual use situations. During user studies in
a smaller research project [9], users were asked about their
experience of the AR system, and none of them even mentioned
desktop or laptop computers, or programs when describing what
they were interacting through or with. Instead, words like robot,
video game and instructor were used to describe the interaction.
The AR system was thus perceived as introducing other properties
to interaction than “normal” desktop applications. This could
hardly be attributed to the content of the interaction (which mainly
was simple instructions of operation), but rather to the fact that the
content was presented directly in the context of use. This of
course raised questions of how useful it really is to base design of
AR systems on desktop computer metaphors and usability criteria.
A previous user study of an AR system at a hospital has indicated
that CSE may be a valid approach to usability issues in AR
systems [24].
The purpose of the system is another important issue – is it
intended for pleasure and fun or if it is part of a work setting? If it
is somewhat forced on the user by it being part of everyday work
and mandatory tasks, the system needs to reach efficiency
standards that may not be equally important if it is used as a toy or
entertainment equipment. If the system is a voluntary toy the
simplicity factor is more important than the efficiency factor [11].
However, if a system is experienced as entertaining, chances are it
may be perceived as being easier to use.
Davis describes two important factors that influence the
acceptance of new technology, or rather information systems, in
organizations [4]. The perceived usefulness of a system and the
perceived ease of use both influence the attitude towards the
system, and hence the user behavior when interacting with the
system, as well as the actual use of the system (see figure 2). If the
perceived usefulness of a system is considered high, the users can
Figure 2. The Technology Acceptance Model derived from [17].
accept a system that is perceived as less easy to use, than if the
system is not perceived as useful. For AR system this means that
even though the system may be awkward or bulky (head
mounted), if the applications are good, i.e. useful enough, the
users will accept it. Equally, if the AR system is not perceived
useful, the AR system will not be used, even though it may be
easy to use.
3. CSE - A HOLISTIC APPROACH
Traditional approaches to usability and human computer
interaction assumes a de-composed view with separate systems of
humans and artifacts The idea of the human mind as an
information processing unit which receives input and generates
output has been very influential in the domain of Human
Computer Interaction (HCI). A basic assumption in the
information processing approach is that cognition is studied as
something isolated in the mind. A problem with many of these
theories is that they mostly are based on laboratory experiments
investigating the internal structures of cognition, and not on actual
studies of human cognition in an actual work context [5].
A holistic approach to human-machine interaction has been
suggested by Hollnagel and Woods called ‘cognitive systems
engineering’ (CSE) [12, 13]. The approach is loosely based upon
findings and theories from, among others, Miller, Galanter and
Pribam [21] and Neisser [22]. The traditional definition of
cognition as something purely mental is questioned in this
approach: “Cognition is not defined as a psychological process,
unique to humans, but as a characteristic of system performance,
namely the ability to maintain control. Any system that can
maintain control is therefore potentially cognitive or has
cognition” [13].
In the CSE approach is important to see the system as a whole and
not study the parts in isolation from each other. The cognitive
system can be comprised of a human and a computer, a human, a
computer, a telephone and another human and so forth, where the
human brings in the ‘natural cognition’ to the system and artifacts
or technological systems may have ‘artificial cognition’.
Hollnagel & Woods uses the notion “Joint Cognitive System”
(JCS) to describe systems comprised of both human and
technological components that strives to achieve certain goals or
complete certain tasks [13]. The JCS approach thus has a focus on
function rather than structure, as in the case of information
processing, which is the basis for most traditional HCI. A CSE
approach to humans and the tools they use thus focus on what
such a system does (function) rather than what is (structure). A
consequence of that perspective is that users should be studied
when they perform meaningful tasks in their natural
environments, meaning that the focus of a usability study should
be user performance with a system rather than the interaction
between the user and a system. A design should thus be evaluated
based both on how users actually perform with a specific artifact,
but also how they experience that they can solve the task with or
without the artifact under study.
3.1 Using Artifacts in Different Ways
As stated above, the main constituents in a JCS are humans and
some type of artifact. Hutchins (1999) defines cognitive artifacts
as “physical objects made by humans for the purpose of aiding,
enhancing, or improving cognition” [14]. Hollnagel and Woods
(2005) define an artifact as “something made for a specific
purpose” and depending upon this purpose and how the artifact is
used, it can be seen as either as a tool or as prosthesis [13].
A tool is something that enhances the users’ ability to perform a
task or solve problems. A prosthesis is an artifact that takes over
an already existing function [13]. A hearing aid is a prosthesis for
someone who has lost her/his hearing while an amplifier can be a
tool for hearing things that normally is too quiet to be heard.
Another example is the computer which is a very general tool for
expanding or enhancing the human capabilities of computation
and calculation, or even a tool for memory support and problem
solving. But the computer can also be used to not only enhance
these human capabilities but also to replace them when needed. A
computer used for automating the locks of the university buildings
after a certain time at night has replaced the human effort of
keeping track of time and at the appropriate time going around
locking the doors.
The way someone uses an artifact determines if it should be seen
as a tool or prosthesis, and this is true also for AR systems. AR
systems are often very general and different applications support
different types of use. So as with the computer, AR systems can
be used either as tools or as prostheses and this may affect the
perceived usability and hence the appropriate design of the
system.
4. CASE STUDY OF AR USE IN A
HOSPITAL SETTING
To address usability aspects of a head mounted video see-through
AR system, a user study at a hospital has been conducted. A
general question in focus for the study was to find out whether the
AR system would be accepted as part of the technological support
in a user group working at a hospital. The specific aim was to
investigate user experience and acceptance of AR systems in an
instructional application for medical equipment. The aim of the
analysis in this paper is not to report completion times or error
frequency but rather focus on the user experience and possible
effects of introducing this equipment in daily tasks at a hospital.
4.1 Method of the study
The participants were observed performing a common operating
room (OR) task. They also answered a questionnaire focusing on
their experience of the instructions they were given by the AR
system. The study was recorded on digital video and during the
task, the participants’ view through the video see-through AR
system was also logged in digital video format.
4.1.1 Participants
Twelve participants, all employed at the hospital, participated in
the study. The participants ranged in age from 30 to 60 and
consisted of OR nurses, surgeons and technical staff. All of the
participants had some experience of the surgical instrument they
were asked to put together in the study.
4.1.2 Equipment.
This section describes the technological equipment used during
the user study.
4.1.2.1 Augmented Reality System.
The hardware part, which can be seen in figure 3, includes a
laptop computer (2.00 GHz Intel®Core™ 2 CPU, 2.00 GB RAM
and a NVIDIA GeForce 7900 graphics card), a head mounted
display with a fire wire camera attached and a headset with
earphones and a microphone. The AR system uses a hybrid
tracking technology based on marker tracking; ARToolKit,
(available for download at [10]), ARToolKit Plus [26] and ARTag
[6]). The software includes an integrated set of software tools
such as software for camera image capture, fiducial marker
detection, computer graphics software and also software
developed specifically for AR-application scenarios [9].
Figure 3. The headmounted video see-through AR
system used in the study. Apart from the HMD, a laptop
computer and headset was also used.
4.1.2.2 The trocar
The object used in the study was a trocar, which is a surgical
instrument, used as a “gateway” into a patient during minimal
invasive surgeries (see fig 4a and b). The trocar is relatively small
and consists of seven separate parts which have to be correctly
assembled for it to function properly as a lock preventing blood
from leaking out of the patient’s body.
In this application the objects to assemble were too small to have
several different fiducial markers attached to each part. Instead the
marker was mounted on a small ring with adjustable size which
the participants wore on their index finger (as can be seen on a
participant’s finger in figure 5 and 6 below).
4.1.3 Task
The task the participants in the study had to perform was to follow
AR instructions on how to assemble was a common medical
device, a trocar described above.
4.1.3.1 Instructions and voice input
Instructions on how to put together a trocar are not formalized;
instead they are normally given by more experienced operating
room nurses. To establish realism the instructions designed for the
AR application were based on the instructions given by an OR
nurse at a hospital. The OR nurse was interviewed, observed and
video recorded while giving instructions and assembling a trocar.
The video was the basis for the sequence of instructions and
animations given to the participants in the study. Examples of the
instructions and animation can be seen in figure 5a. Figure 5b
illustrates the setup, where a participant receiving instructions can
be seen.
Figure 5 a and b. To the left the participants view during
the task. To the right a participant following performing
the task.
Before receiving the assembly instructions the users are given a
short introduction to the commands they can use during the task;
“OK” to continue to the next step, and “back” or “backwards” to
repeat previous steps. The voice input is received through the
headset microphone and is interpreted by the MS windows speech
recognition module and then interpreted by the MR software.
4.1.4 Data collection
Data was collected both through observation and through
questionnaires. The questionnaire responses were described and
analyzed. The observation was mainly focused on the general
interaction with, and through the AR system.
4.1.4.1 Questionnaires
Figure 4a and b. To the left the trocar fully assembled. To
the right the pieces to be assembled by the participants in
the user task.
The first part of the questionnaire consisted of a set of closed
questions where the participants responded on a 6 point likert
scale (see figure 6 below). In total the questionnaire included 17
closed questions of which the first 3 were demographical in nature
(prior technological experience, interest in technology and
computer use). The remaining 14 questions focused on the user
experience with statements where the user could check a box
between “completely agree” to “completely disagree”. The
statements included topics such as learning time, understanding of
instructions, ability to assemble new objects, the clumsiness of the
system, experiences of nausea, experienced control and difficulty
of use as well as fun to use. Three questions of particular interest
for the study was whether or not the users would be prepared to
use an AR system for similar tasks in their work, and in other
situations than work, and if it was fun to use (see figure 6).
The second part of the questionnaire included 10 open questions
were the participants could elaborate on their experience of the
AR system. The questions covered overall impression of the AR
system, experienced difficulties, experienced positive aspects,
what to change in the system and whether it is possible to
compare
AR ofinstructions
the statement
system tofrom
receiving
Figure 6. receiving
An example
a likert scale
the
instructions
from a teacher.
questionnaire.
where the users responded to whether they would prefer to receive
instructions from a teacher or tutor. It is perhaps no surprise that
in general the participants would prefer human to human
interaction to interacting with a technical system.
The question that received the highest scores was a question
regarding general ergonomics – none of the participants
responded that they experienced any discomfort during the use of
the system. The lowest grade was a 5, which shows that no one
agreed to the statement of having experienced any discomfort.
The questions most related to the general aim of this paper related
to whether or not the participants would like to use this system in
their profession (see figure 7).
4.2 Results and Analysis
This section describes the results of the study. First the results of
the closed response questionnaire are briefly reported and
discussed. In the following paragraphs the results of the openended questions and observations are analyzed and correlated.
4.2.1 Closed questions
The participants gave responses on a 6 level likert scale and the
likert scale was transformed into a 6 degree grading system,
where 6 was the most positive answer for the AR system (e.g. the
user for instance completely agrees that the system was fun to use,
or completely disagrees that the system was clumsy to use) and 1
was the most negative. The results from the closed part of the
questionnaire can be seen in the table below.
Table 1. Statements in the closed response questionnaire.
Question/statement
Average
4. It was easy to understand the instructions.
4,92
5. The text was difficult to read due to color or size.
4,67
6. It took a long time to learn to use the system
4,67
7. This system is difficult to use.
4,67
8. I felt in control over the system.
3,67
9. I would like to use this type of system to receive
instructions in my profession.
4,58
10. I would like to use this system in other contexts than
my profession.
3,75
11. With this system I can assemble objects which are
new to me.
4,58
12. I feel confident that the system is giving me correct
instructions.
4,25
13. I would prefer to receive instructions from a person
(teacher/tutor)
3,25
14. This system is clumsy to use.
4,25
15. The system does not have any apparent shortcomings
3,55
16. I experienced nausea, dizziness or discomfort while
using the system
5,67
17. This system is fun to use.
4,50
Table 1: The statements/questions in the closed response
questionnaire. In the right column the average response
score is shown.
As can be seen in the table, the scores in general are on the upper
part of the scale. The lowest score can be found in question 13,
Figure7: The responses to statement 9 “I would like to use
this system in my work”
As can be seen in the graph one of the participants definitely does
not want to use this kind of system in their work, while 4 others
definitely do want to use this kind of system in their work.
Interestingly enough one participant, who would like to use the
AR system at work, does not find it fun to use (see figure 8
below).
Figure 8: The responses to statement 17 ”This system is
fun to use”.
Overall the participants did find the system fun to use, the average
score was 4.50 and 7/12 gave the score 5 or six.
4.2.2 Observations and open ended questionnaire
The open ended questions were transcribed and are reported here
as a brief summary under separate themes. They are discussed in
relation to observations made during the study as well as during
analysis of the video recorded material.
4.2.2.1 Marker problems
Many of the participants commented on the marker as being
problematic. The problems arise when the marker is obscured in
one way or another (mostly due to movements of the hand) and
the AR system looses contact with the marker and then when the
marker is identified the last viewed instruction is repeated. That
this is problematic is illustrated by the video data, which shows
how the participants move their hands to get the marker in clear
view. This may affect the perceived ease of use of the AR system
and contribute to the experienced clumsiness of it.
4.2.2.2 Multimodality
Concerning the multimodal aspects of the instructions, receiving
both aural and visual instruction seemed to increase the perceived
ease of use of the system:
“The voice control + text and image. You just
can’t do wrong.” (participant 2)
However it also confused one of the users answering the question
of there was anything that s/he experienced as troublesome:
“to both listen and look, hard to see what part to
use” (participant 11)
4.2.2.3 Instructions
A majority (8/12) of the participants experienced the instructions
as clear and easy to follow:
“Simple, compared to if you by reading text are
trying to obtain the same information.” (participant
4)
“Easy to understand the instruction. Easy to use.”
(participant 3)
The quote by participant 3 illustrates the relation between good
design of instructions and the overall impression of the system.
Overall the participants seemed to cope well with working
through the AR system, and most of them found the system fun to
use (as also can be seen in question 17 in the closed
questionnaire). The idea of a system being fun to use is a positive
factor when introducing new technology into a work place. As
noted above, when users of a system find it entertaining, they may
be able to cope with more complex and more difficult systems.
However, it still must be perceived useful for their task, or it
becomes redundant.
4.2.2.4 Comparing the AR system to other systems
All of the respondents work with computers on a day to day basis
and are accustomed to traditional MS Windows™ based graphical
user interfaces but they saw no similarities with the AR system.
Consistent with the findings in a previous study [9], most of the
respondents referred to interacting with or through a computer
when asked what the interaction felt like. Most of them (9/12) did
not find any comparison at all, but the few that did, did not
mention other computer aided instructional systems, but instead
laparoscopic surgery, and computer games.
The respondents are usually introduced to new technology and
equipment through more experienced staff, or sometimes by the
company selling the product. One problem with receiving
instructions from colleagues and other staff members are that the
instructions are not ‘objective’, but more of “this is what I usually
do”. The only ‘objective’ instructions available are the manual or
technical documentation and reading this is time consuming and
often not a priority. When asked about the possibility to compare
the AR system with receiving instructions from a teacher one
response was this:
“What you can be sure about with this system is
that everyone has gotten the exact same
information.” (participant 4, emphasis by
participant)
The differences within the group, and the fact that there are only
twelve participants, make it difficult to draw any general
conclusions from the results of the responses, but the individual
comments are nonetheless relevant to the further development of
the AR system.
5. DISCUSSION – THE CSE
PERSPECTIVE AND AR DEVELOPMENT
Human face to face interaction is perhaps the most common way
to receive instructions on how to operate new equipment, and by
imitating this personal interaction the AR system illustrates a big
advantage to other forms of instructions. The instructions are
presented in real time right in the user’s field of view allowing
users to experience the instructions in actual context. If the AR
system should be viewed as tool or prosthesis is in this regard
difficult to answer. It is a tool in the sense that it provides
instruction, allowing the user to perform tasks efficiently.
However, it also, as reported above, in some sense replaces the
interaction with peers, potentially disturbing an important part of
the human interactivity in the learning process. Feedback is, after
all, limited and it is currently not possible to ask the system
clarifying questions.
By confronting a design for a new technology with tasks from real
work rather than laboratory settings allows problems that probably
otherwise would remain unknown to emerge. In a laboratory
experiment or evaluation, the user is confronted with a situation
based on assumption about what is relevant that originates from
the researcher/evaluator. A common approach in many
experimental studies is to present the experiment participant with
a “nonsense” task, deliberately removing any connections to
actual work. The CSE approach instead suggests that conclusions
about pros and cons of a new system should be drawn in its
intended use setting. This is especially true when concerned with
tools that are to be used by specialists in high-risk environments.
A product like the trocar represents such a tool used for a highrisk task by skilled professionals. It is also clearly a case where
improved functionality in terms of instructions is beneficial, since
objective instructions has a potential to reduce erroneously
performed assemblies of the trocar. Testing the concept of
providing AR instructions together with such instruments in a
real-world setting thus reveal the pros and cons of a design.
Cognitive Systems Engineering provides a way to study and think
about AR systems as joint cognitive systems acting in a goal
oriented and adaptive way in the world. These fundamental
aspects are lacking in most other perspectives where interactions
mostly is studied on a micro-level.
Another aspect of the system that becomes evident when
observing users in their actual work environment is its physical
appearance and bulkiness largely originating from the technical
limitations of using video see-through HMDs. Despite some
physical issues with the AR system all users did complete the task
without any other assistance. However, effects of the physical
intrusion of the system upon the user’s normal task should not be
ignored. Even if the system is lightweight and non-intrusive, it
still may change the task and how it is performed. In the worst
case users may abandon the system if the experience it as too
clumsy. Regardless of appearance, any system does affect the
social context of the task simply by being introduced as a new
element. However, this may not be a problem in the long run – if
the system is a positive influence on the task, user and context, it
will with time and experience grow to be a part of the task. This
should be true for AR as it has been true for other technologies;
for instance the use of computers for writing papers – few
students and researchers today can image writing papers without
the cut-and-paste functionalities of word processors. To fully see
the effects of introducing an AR system into a hospital
environment a more longitudinal study involving an application
like the one presented in the case study may be required.
One aspect, not to be forgotten, is the positive results of the
question of enjoying the use of the system. A majority of the
participants found the AR system fun to use and work with, and
several of them also wanted to use it as a part of their work. The
technology acceptance model implies that the perceived ease of
use and perceived usefulness of a system is what determines if
users will actually use it in the end. The experienced ease of use is
most likely influenced by the enjoyment of using a system. If it is
fun to use, it may be experienced as easier to use, and vice versa.
Entertainment in varying degrees is an important usability factor
for all user interfaces, even though there are obvious examples of
experienced usefulness weighing heavier than both ease of use,
and entertainment.
Although user acceptance of the AR system in the case presented
above was high, there are several issues to overcome before AR
instructions can be an acceptable part of work at a hospital. In the
current setup the AR system has some important shortcomings –
the lack of dialogue for one thing. As pointed out, the user must
have the ability to interact more freely, i.e. asking questions. The
way to position markers so that they are not obstructed during the
assembly is also an important issue.
6. SUMMARY AND CONCLUSIONS
This paper has presented a discussion on acceptability and
usability of an AR system in a hospital task. The discussion is
based both on the results of a qualitative user study and the
theoretical basis of CSE. The study was conducted in a
naturalistic setting, on site at a hospital with actual users and their
equipment. The CSE approach to usability supports the idea of
doing practical research in the actual use context to make sure that
the research considers all aspects of use, including the social
impact of the studied system. The analysis of the results has
indicated that although there are some ergonomic issues to be
solved, the acceptance of an AR system in this user group is high.
A majority of the participants were positive towards the use of AR
in their work environment, and especially as a supportive tool for
learning how to assemble or use new technology. Due to the
envisioned world phenomena described in the introduction of this
paper it is clearly so that the design of AR systems is a constantly
ongoing iterative process, and as such further usability studies on
the recently implemented changes will be conducted. The process
is likely to go on until the changes conducted between the
iterations become so small that they have moved from major
usability issues to esthetical, social or personal issues.
7. ACKNOWLEDGEMENTS
This study is part of a collaboration project between the
Department of Computer and Information Science (IDA) at
Linköping University, and the Swedish Defence Research Agency
(FOI), funded by the Swedish Defence Materiel Administration
(FMV).
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