Control of virtual environments for young people with learning difficulties

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<ul><li><p>Control of virtual environments for youngpeople with learning di culties</p><p>T. LANNEN*, D. BROWN and H. POWELL</p><p>Department of Computing, Nottingham Trent University, UK</p><p>Abstract</p><p>Purpose: The objective of this research is to identify therequirements for the selection or development of usable virtualenvironment (VE) interface devices for young people withlearning disabilities.Method: A user-centred design methodology was employed, toproduce a design specification for usable VE interface devices.Details of the users cognitive, physical and perceptual abilitieswere obtained through observation and normative assessmenttests.Conclusions: A review of computer interface technology,including virtual reality and assistive devices, wasconducted. As there were no devices identified that metall the requirements of the design specification, it wasconcluded that there is a need for the design anddevelopment of new concepts. Future research will involveconcept and prototype development and user-based evalua-tion of the prototypes.</p><p>Introduction</p><p>Recent research in virtual environment (VE) applica-tions for people with learning disabilities has highlightedusability di culties with the computer interface devices,which are used to perform the VE tasks. For example,from an evaluation of VEs, developed to teach indepen-dent living skills to people with learning disabilities, itwas found that individuals diVered in the amount ofsupport required to use the input devices; joystick fornavigation and mouse for interaction.1 This paperdescribes research undertaken to identify the require-ments for the selection or development of usable VEinterface devices for young people with learning disabil-ities.</p><p>VIRTUAL ENVIRONMENTS</p><p>VEs have been found to be of educational benet forpeople with learning disabilities.2, 3 Before describingthese benets, what are VEs? They are three-dimen-sional computer simulations, which respond in real timeto the activity of their users, see gure 1. One of the rstapplications of VE technology was in ight simulationto train pilots within a safe environment. Their use iscontinually progressing in many areas, such as architec-ture, medicine, rehabilitation and education. There aretwo independent phases of operation within a VE: navi-gation and interaction. Navigation, with 2 degrees offreedom, allows movement forwards, backwards andturning to the left or right. Interaction includes activat-ing VE objects (i.e. opening a door), moving VE objectsfrom one place to another or using one object withanother (i.e. using a spoon to take some sugar from asugar bowl). The sense of presence within a VE is depen-dent on the input and display devices used. A high levelof participant immersion can be achieved using a head-mounted display with a specialised input device, such asa data-glove. Desktop VE systems are also in wide-spread use, which utilise a computer monitor to displaythe VE and standard input devices, such as a joystick,mouse or keyboard, see gure 2. This hardware combi-nation can also lead to a sense of presence and generally,desktop systems are preferred when working with peoplewith learning disabilities due to the unresolved healthand safety issues and high cost associated with head-mounted display units.</p><p>VE BENEFITS</p><p>Research has indicated numerous benets in the useof VEs for the education and training of people withlearning disabilities.1, 2 They encourage active participa-tion in learning and give the user control over the learn-ing process. They facilitate playful activity, by allowingindividuals to learn by making mistakes without suVer-</p><p>* Author for correspondence; e-mail:</p><p>DISABILITY AND REHABILITATION, 2002; VOL. 24, NO. 11-12 , 578 586</p><p>Disability and Rehabilitation ISSN 09638288 print/ISSN 14645165 online # 2002 Taylor &amp; Francis Ltd 10.1080/0963828011011134 2</p><p>Dis</p><p>abil </p><p>Reh</p><p>abil </p><p>Dow</p><p>nloa</p><p>ded </p><p>from</p><p> info</p><p>rmah</p><p>ealth</p><p>care</p><p>.com</p><p> by </p><p>Uni</p><p>vers</p><p>ity o</p><p>f N</p><p>orth</p><p> Tex</p><p>as o</p><p>n 11</p><p>/30/</p><p>14Fo</p><p>r pe</p><p>rson</p><p>al u</p><p>se o</p><p>nly.</p></li><li><p>ing the consequences of their errors. VEs are describedin terms of realistic and graphical representations ofthe real world. Hence, they avoid abstract thought,which has been found to be particularly di cult forpeople with learning disabilities, who are often describedas `concrete thinkers.3 Finally, they can minimize theeVects of many physical disabilities and allow studentsto take part in activities or visit places that might beinaccessible to them in real life.</p><p>MOST SUITABLE INPUT DEVICES</p><p>Studies on the most appropriate methods of VEcontrol for people with learning disabilities have beenconducted. Hall4 concluded that a joystick, limited totwo simultaneous degrees of freedom, had the greatestutility in VE navigation tasks. A study by Brown etal.5 found that the joystick was more suitable for naviga-tion tasks than the keyboard or mouse. The touch-</p><p>screen and mouse were assessed for interaction tasksand the students coped very well with both devices,however, di culties were found in using the touch-screen to interact with small objects and with calibrationof this device. From these studies it can be concludedthat, from the range of input devices tested, the joystickand mouse are the most suitable navigation and interac-tion devices respectively.</p><p>USABILITY DIFFICULTIES</p><p>Neale et al.6 conducted an evaluation of VEs for theeducation of children with severe learning disabilities.The devices utilised in this study were the joystick fornavigation tasks and the mouse or touch-screen forinteraction tasks. It was found that:</p><p>. restricted movement space was di cult to navigateand led to user frustration; and</p><p>. teacher assistance was required for some interactiontasks.</p><p>It is important to note that participant selection forthis study was based partly on ability to control theinput devices. Although the navigation di culties foundwere software related, it is the authors belief that, theoverall usability of the system would be enhanced byrening the input devices as well as the software inter-face. In the aforementioned study by Cobb et al.,1 itwas found that individuals diVered in the amount ofsupport required to use the input devices; joystick fornavigation and mouse for interaction. It was also statedthat navigation was found to be one of the most di culttasks to do. This research by Neale et al.6 and Cobb1 hasshown that there are usability di culties with the inputdevices, which have been found to be the most suitablefor navigation and interaction tasks, from the range ofdevices tested by Hall4 and Brown et al.5</p><p>SOLUTIONS</p><p>From the study by Brown et al.5 the following require-ments for input device design or renement were identi-ed: operable by people with ne-motor di culties,modiable, robust, easy to calibrate and aVordable.Lannen7 developed a prototype interface device, theMojo interactive seat, which meets some of theserequirements: operable by people with ne-motor di -culties, modiable and aVordable, see gure 3. Mojowas compared with a joystick for control of a VE navi-gation task by students with moderate to severe learningdisabilities, some of whom were also physically</p><p>Figure 2 A standard input device for controlling virtual</p><p>environments.</p><p>Control of VEs for young people</p><p>579</p><p>Dis</p><p>abil </p><p>Reh</p><p>abil </p><p>Dow</p><p>nloa</p><p>ded </p><p>from</p><p> info</p><p>rmah</p><p>ealth</p><p>care</p><p>.com</p><p> by </p><p>Uni</p><p>vers</p><p>ity o</p><p>f N</p><p>orth</p><p> Tex</p><p>as o</p><p>n 11</p><p>/30/</p><p>14Fo</p><p>r pe</p><p>rson</p><p>al u</p><p>se o</p><p>nly.</p></li><li><p>impaired.8 From the results it was clear that less disor-ientation occurred when using Mojo, however, bothdevices would require renement to provide an adequatesolution to this human-VE interaction problem.A review of computer interface technology, including</p><p>virtual reality and assistive devices, was conducted.Assistive devices have been designed to improve accessto computers for people with a wide range of disabilities,for example voice and gesture recognition, eye and headtracking and brain wave control. However, no researchhas been found which investigates the use of suchdevices for the control of VEs for people with learningdisabilities. It has also been expressed that the cost ofthe technology mentioned would currently be too greatfor most individuals and some organisations.5</p><p>CONCLUSION</p><p>The research by Neale et al.6 and Cobb1 showed thatthere are usability di culties with the joystick andmouse, which were found to be the most suitable devicesfor people with learning disabilities to control VE tasks.However, this research was not specic about the kindsof di culties that are experienced with these devices.Therefore it was decided that the next step would beto conduct a thorough evaluation of the joystick andmouse, in order to identify the specic usability di cul-ties experienced and to clarify how research shouldprogress.</p><p>INPUT DEVICE EVALUATION</p><p>Aim</p><p>To identify the usability di culties, which youngpeople with learning disabilities experience when usingthe joystick and mouse for VE navigation and interac-tion tasks respectively.</p><p>User group</p><p>Fourteen students were selected from the ShepherdSchool in Nottingham to form the user group. The usergroup attributes were as follows:</p><p>. gender: 7 female and 7 male;</p><p>. age range: 7 to 19;</p><p>. cognitive ability: 2 moderate/severe and 12 severelearning disabilities; and</p><p>. physical ability: co-ordination, gross-motor and ne-motor di culties.</p><p>Environment</p><p>The evaluations took place at the Shepherd School, intheir `Cyber Cafe room. For some evaluations, theroom was quiet and mostly free from distraction.During the majority of evaluations, other studentswould come and go from the room, but would notattempt to disturb the user.</p><p>Equipment</p><p>The VEs were displayed on a colour computer moni-tor and a standard two-button mouse was used for inter-action tasks. Initially, the Axys joystick (SuncomTechnologies) was used for navigation tasks. However,as some of the students were experiencing di culties ingripping the stick on this device, the last 4 students usedthe Wingman joystick (Logitech). The stick on theWingman joystick is much taller and wider than theAxys joystick and is shaped to t the hand, see gure 4.</p><p>Task</p><p>Each student was asked to complete navigation andinteraction tasks, using the joystick and mouse respec-</p><p>Figure 3 Mojointeractive seat for VE navigation.</p><p>T. Lannen et al.</p><p>580</p><p>Dis</p><p>abil </p><p>Reh</p><p>abil </p><p>Dow</p><p>nloa</p><p>ded </p><p>from</p><p> info</p><p>rmah</p><p>ealth</p><p>care</p><p>.com</p><p> by </p><p>Uni</p><p>vers</p><p>ity o</p><p>f N</p><p>orth</p><p> Tex</p><p>as o</p><p>n 11</p><p>/30/</p><p>14Fo</p><p>r pe</p><p>rson</p><p>al u</p><p>se o</p><p>nly.</p></li><li><p>tively, within a virtual factory, cafe or supermarket.Demonstrations of the devices and tasks were givenbefore commencing the evaluations.</p><p>Assessment measures (AMs)</p><p>. misuse of device: non-task related movement,harshness, pressing the wrong buttons, etc.;</p><p>. support required: spoken instruction, physicalassistance, etc;</p><p>. physical ability: su cient strength, able to gripproperly, etc.;</p><p>. workplace: able to reach, etc.;</p><p>. attention: on task, on device, on other; and</p><p>. user comments/reactions: positive, negative.</p><p>RESULTS: USABILITY DIFFICULTIES</p><p>Due to physical ability and device construction eightof the students in the user group were able to controlthe mouse and the joystick they evaluated quite well.However, this group still experienced usability problemswith the devices (identied using AMs 1 3): too muchleft/right rotation, button misuse, base held still byexaminer and grip di culties with the joysticks; baseheld still to press button and grip di culties with themouse. In the authors opinion, these di culties arelargely due to the construction of the devices and thephysical abilities of the user group, rather than to theusers understanding of how to use each device. It wasobserved that the Wingman joystick is easier to gripthan the Axys joystick, due to its size and shape, high-lighting the importance of ergonomic design for increas-ing usability.</p><p>Due to cognitive ability</p><p>It is the authors belief that the di culties experiencedby the remaining 6 members of the user group arerelated to their cognitive understanding of how to use</p><p>the devices: random movement and trying to use forinteraction with the joysticks; random movement andfrequent pressing of buttons with the mouse (identiedusing AM 1). To overcome these di culties it may benecessary to gain a deeper knowledge of the userscognitive and perceptual abilities, so that the devicescan be rened to an appropriate level of understanding.</p><p>Due to task and environment</p><p>As the joysticks and mouse were not specicallydesigned to be used by people with learning disabilitiesto control VEs, there may be certain VE tasks for whichthey are more di cult to use. This is evident from thisevaluation, as physical help was required with the inputdevices to complete some tasks by 12 of the students.For example, one student required physical assistancewith the Axys joystick to align his position in front ofthe exit doors in the virtual factory. Finally, 5 membersof the user group were distracted by other students andactivities in the evaluation room (identied using AM 5).Design guidelines were suggested, which should help tofocus the students attention on the VE, for example,`workstation helps to engage the user.</p><p>CONCLUSION</p><p>This evaluation has highlighted the importance ofconsidering the physical and cognitive abilities of theuser group, as well as the tasks that the user mustcomplete with the input devices, and the environmentin which the tasks will be performed, in order to developa usable computer interface device. This theory isbacked up by contemporary human-computer interac-tion (HCI) research, which also stresses that you shoulddesign for the user, the task and the environment.9 Inuser-centred design, the rst research activity performedis to `understand and specify the context of use. Thiscan be achieved by conducting a Usability ContextAnalysis (UCA), which involves a user, task and envir-onmental analysis. Therefore, it was decided that auser-centred design methodology would be employedin order to ascertain the requirements for the selectionor design of usable VE input devices, for young peoplewith moderate/severe learning disabilities.</p><p>User-centred design</p><p>METHODOLOGY</p><p>Usability is a crucial factor in the production of asuccessful human-computer interface and is central to</p><p>Figure 4 The Wingman joystick (Logitech) and the Axys joystick</p><p>(Suncom Technologies).</p><p>Control of VEs for young people</p><p>581</p><p>Dis</p><p>abil </p><p>Reh</p><p>abil </p><p>Dow</p><p>nloa</p><p>ded </p><p>from</p><p> info</p><p>rmah</p><p>ealth</p><p>care</p><p>.com</p><p> by </p><p>Uni</p><p>vers</p><p>ity o</p><p>f N</p><p>orth</p><p> Tex</p><p>as o</p><p>n 11</p><p>/30/</p><p>14Fo</p><p>r pe</p><p>rson</p><p>al u</p><p>se o</p><p>nly.</p></li><li><p>the user-centred design process. The usability of aproduct is dened in ISO 9241, part 11 (the British Stan-dard giving guidance on usability) as `the extent to whicha product can be used by specied users to achieve speci-ed goals with eVectiveness, e ciency and satisfaction ina specied context of use. According to the ISO 13407standard (human centred design processes for interactivesystems) the key activities in user-centred design are:</p><p>. understand and specify the context of use;</p><p>. specify the user and organisational requirements;</p><p>. produce...</p></li></ul>


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