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Presented to ICCHP 2000. International Conference on Computers Helping People with Special needs.        
Karlsruhe (Germany) 17-21 July 2000.            
http://szswww.ira.uka.de/icchp2000/wgs.htm

Web accessibility for people with
motor impairments. Case studies

Ferrer, A.M.; Romero, R.; Alcantud, F.
Research Unit Acceso http://acceso.uv.es

Dpto. Psicología Evolutiva y de la Educación

Universitat de València Estudi General (Spain)

In this paper we present an evaluation of computer accessibility for web browsing in seven motor impaired users utilising different assistive technology solutions. The best access system has been found to be very dependent on user characteristics. Thus, each case needs to be treated individually and different assistive technology tried to determine which best suits that particular user.

1. Introduction

The most representative element of the new Information Society is, without any doubt, the World Wide Web that connects millions of computers from multiple places with an amount of information at your fingertips not previously known and a graphical and intuitive interface that is contributing to its exponential expansion, in terms of number of web sites, pages and users all over the industrialised world. However, the Web presents certain barriers for some user groups, for example, although not only, people with disability. These are the so called accessibility problems, and affect mainly to vision-impaired and motor-impaired disabled users. We will concentrate for this paper in the last ones. There are people with physical disabilities that encounter difficulties to navigate efficiently through computer environments, and more specifically, in those applications intended for browsing the web.

Web accessibility refers to the ability for any user and in particular people with disability to access the information contained in World Wide Web and to perform the tasks implicit in its use. When accessing the web, and from the point of view of accessibility for people with physical disabilities, a chain of three elements exists between the user and the content of the web site involved [1]. These are 1) the accessibility to the computer, 2) the accessibility to the browser and 3) the accessibility to the web design. Each one of them should work correctly in its role and in their interaction with the other elements for accessibility to take place. In this paper we present an experience of evaluating the first aspect, that is, the computer accessibility for web browsing, in motor impaired users utilising different assistive technology solutions. A lot of information regarding accessible browsers and web design can be found in WAI web site [5].

2. Case study

2.1. User group and assistive technology

We have analysed how seven disabled users browse the web, each of them using two access system in particular and performing a set of tasks related to web browsing. For each of them we tried the access system regularly used and another one proposed for testing in the moment of the evaluation, according the evaluator criterion. See table 1 next.

User	Years web experience	Usual access system	Alternative access system
PC	1.5	On screen Keyboard Track-ball	On screen Keyboard with word prediction Track-ball
CB	3	Standard keyboard Track-ball	Voice recognition Track-ball
JR	4	On screen Keyboard Standard mouse	On screen Keyboard Joystick with switch
JJ	3	Standard keyboard with stick Standard mouse	On screen Keyboard Head Master mouse with switch
RB	2	Standard keyboard Track-ball	On screen Keyboard Tactile screen
MLL	1	Standard keyboard Standard mouse	Voice recognition
CP	2	Standard keyboard with: -         Head stick -         Protective case	Standard keyboard with Windows 98 accessibility options -         FilterKeys -         StickyKeys -         MouseKeys)

Table 1. User summary

Due to space considerations we only present next a succint summary of the seven cases:

Case PC. Male, 17 years old. Degenerative illness Werdnig-Hoffman. Uses oral language with great difficulty. He can only move left hand, better movement in index finger. Uses on-screen keyboard My-T-Mouse with track-ball integrated in EZ-Ball keyboard.

Recommendation: use alternative keyboard with word prediction to improve typing speed which is the critical task for him.

Figure 1. User with track-ball mouse integrated in keyboard

Case CB. Female, 41 years. Cerebral Paralysis with spastics cuadriparesia. Uses oral language with some difficulty. Can move hands to use ordinary keyboard but very slowly. Uses standard keyboard, track-ball mouse and voice recognition (Dragon Dictate Classic Edition), although not for browsing.

Recommendation: no clear superiority of any system. Keep using all of them combined and learn Dragon Dictate specific functions to speed up browsing.

Case JR. Male, 38 years, Lateral Amiotrophic Esclerosis (degenerative). Oral language not good enough for voice recognition. Can perform small weak hand movements. Moves standard mouse using both hands at the same time. Uses on-screen keyboard personalised with "Discover".

Recomendation: use joystick mouse with right hand and switch for click with left hand. His degenerative illness will imply in the future  the use of scanning system.

Case JJ. Male, 26 years, medular lesion. Good oral language. Can move both hands. Use standard mouse with right hand but can not type normally. Use a hand held stick for typing in standard keyboard.

Recommendation. After trying Head-Master (a head controlled mouse with infrared system) and My-T-Mouse on screen-keyboard, no significative improvement appeared. Thus, keep using present acces system.

Case RB. Female, 24 years, cerebral paralysis with spastic-distonic cuadriparesia. Can not use oral language. Can move both hands withouth precise control. Can type on standard keyboard but very slowly. Uses track-ball mouse of big dimmension. Presents more difficulties also due to less knowledge of the task domain.

Recomendation: complement with tactile screen. This seems faster but it depends on the size of links and icons on web pages.

Figure 2. User with external track-ball mouse

Case MLL. Male, 18 years, Duchenne type Muscle Distrophy (degenerative). Uses oral language fairly well. Can move both hands for typing but with many errors. Uses standard mouse without problems.

Recomendation: Use voice recognition software Dragon Dictate Classic Edition.

Case CP. Male, 23 years, cerebral paralysis with spastic-distonic cuadriparesia. Can not use oral language. Can move head with fairly good control. Can type in standard keyboard but very slowly, supporting and guiding one hand with the other. Can not use a tactile screen in vertical position. Uses different methods according to work place: head stick for typing, direct typing with keyboard protector case, accesibility options  StickyKeys, FilterKeys, and for mouse emulation, MouseKeys. Very expert in alternative key access to Windows and browser functions.

Recommendation: Try browser Opera, due to its extensive keyboard support.

2.2. Test methodology

We designed a series of tasks to invite the users to perform several characteristic actions involved in web browsing (to visit different web sites, to search information, to introduce data, to download files…) with the evaluator help. See table 2.

Table 2. Web browsing task list for the test

To analyse this experimental evaluation, we considered three observation based evaluation protocols:

·        All the users were observed in its execution (direct observation). 

·        The execution was analysed again watching the videotape recording (indirect observation).

·        After doing the tasks, each user completed an evaluation grill with several questions.

Recommendation for the use of access system was based on user performance in the test tasks.

3. Results and conclusions

In all cases the best access system has been found to be completely dependent on user characteristics. Thus, each motor impaired user case needs to be treated carefully and individually by trying different assistive technology to determine which pool of hardware and software best suits that particular user. It is therefore very important that the user and the evaluator have good and updated knowledge of all available assistive technology in the market [2], [3].

As general conclusion, if the disabled user can still use the input devices efficiently (mouse or any other device that emulates its functions and ordinary keyboard or on-screen-keyboard with direct selection), this should be the first option as the web browsing tasks will only present similar difficulties to what we could foresee for an average web user. In any case, the performance could be worse, but still acceptable, due to the speed and motor skills of each person. This is the case for PC, JR and JJ.

Sometimes standard or adapted devices can not be used, or the access is very slow and difficult. Then if the possibility exist of using oral language with proficiency it would be recommended to select as first option the use of a Voice Recognition System that allow to interact with the computer in hands-free mode. In this sense, Dragon Dictate Classic Edition 3.0 seems an interesting option as it incorporates some specific functions for Internet Explorer control. In cases with moderate speech production problems Dragon Dictate can still produce acceptable results in voice recognition but it must be stressed the need for dedicating enough time to "train the system" initially to adjust it to the user voice. This system, complemented with the other access method already used, has been recommend to users CD and MLL.

In the case of users without speech or poor oral language, and depending on the difficulties for the hands movement, we could opt for direct keyboard access with diverse accessibility options. If the user has only one hand or finger, it is useful to activate Windows 98 StickyKeys for being able to press key combinations sequentially. For example: Control+Alt+Supr. To complement this the MoseKeys option allows to control the mouse with the numeric keypad. Then it also could be interesting to try another browser like Opera which has all of its functions available through shortcut keys. This was recommended to CP.

For some users, when visiting a web site with many links, it maybe useful to use a tactile screen that would allow to work more efficiently by direct selection of the point of interest in comparison with the keyboard or mouse manipulation. For this solution it is necessary that a minimal motor precision exist to finger-point correctly on the links showed in the screen. This was the case of RB.

In the case of controlling the browser using only the keyboard some difficulties may appear when following the focus evolution in the screen as it might not be visually obvious which element is being highlighted each time, specially if the link is within an image. This is mostly a web page design problem. However this can be partially solved by applying by default a user defined Cascading Style Sheet in the browser that highlights the active link with different colour, font weight and even placing a rectangle around it.

Finally, the needs of those users whose severe motor impairments force them to the exclusive use of a switch controlled scanning systems to work with the computer can not be properly addressed nowadays. Unfortunately this is the case for the last stages of users with degenerative neuronal diseases. In these cases we do not find adaptations available neither as freeware/shareware nor as commercial applications and we must opt for tailor-made solutions based on existing authoring tools like Ace Centre Switch Access to Windows (SAW) or general purpose programming languages like Visual Basic. But the programming option is very expensive in terms of development cost, specially when we consider that the present evolution of Internet can make obsolete any browsing application in as soon as a couple of years.

4. Acknowledgements

This research was carried out during the project ACCESO25 of the ESF Horizon Initiative with the co-financing of Universitat de València Estudi General, as part of our university contribution to the project final report of the transnational partnership ATIN [1].

5. References

[1]     ALCANTUD, F.; FERRER, A. & ROMERO, R. (1999) Analysis of web pages accessibility and usability for physically disabled users: Case studies. Final report for transnational Horizon project ATIN.

[2]     ANSON, D.K. (1997) Alternative Computer Access: a Guide to Selection. IOS press.

[3]     CUNNINGHAM, C.& COOMBS, N. (1997) Information access and adaptative technology. American Council on Education, Oryx Press.

[4]     ROMERO, R., ALCANTUD, F, FERRER A.M. (1998) Estudio de Accesibilidad a la Red. Universitat de València Estudi General http://acceso.uv.es/accesibilidad/estudio/PAGEAUTH.htm

[5]     WAI: WEB ACCESSIBILITY INITIATIVE (1999) Web Content Accessibility Guidelines version 1.0. World Wide Web Consortium. http://www.w3.org/wai