Web Accessibility for Disabled Users: Design and Testing

Introduction

The objective of this work is to research methods used for making web-based information more accessible to people with disabilities — specifically users with blindness, low vision, motor restrictions, and dyslexia. The World Wide Web Consortium (W3C) has issued guidelines intended to make browsers and multimedia players more accessible to persons with disabilities. Examples of enabling technologies include making browser commands accessible via keyboard for those who cannot use a mouse, and support for screen reader technology, which intercepts what is displayed on a screen and directs it to a speech synthesizer or refreshable Braille device for the blind (Krill, 2002).

Scope of the Disabled Population

In his work "Accessible Design for Users with Disabilities," Jakob Nielsen states that "the most serious accessibility problems given the current state of the Web probably relate to blind users and other visual disabilities, since most Web pages are highly visual" (Nielsen, 1996). Nielsen further notes that those who are deaf or have other auditory disabilities rarely encounter problems on the Web because sound effects are "usually totally gratuitous."

According to a study conducted in the United States, 428,280 postsecondary undergraduate students were identified as having disabilities, representing approximately 6% of the total student body. The breakdown of disability types was as follows:

• Learning disabilities — 45.7%
• Mobility or orthopedic impairments — 13.9%
• Health impairments — 11.6%
• Mental illness or emotional disturbance — 7.8%
• Hearing impairments — 5.6%
• Blindness and visual impairments — 4.4%
• Speech or language impairments — 0.9%
• Other impairments — 9.1%

(Source: An Institutional Perspective on Students with Disabilities in Postsecondary Education, National Center for Educational Statistics, Postsecondary Education Quick Information System, August 1999)

In order to better understand the scope of the disabled population and their specific needs for full web accessibility and participation, it is useful to examine what students in each disability category require in computer-related learning environments.

Accessibility Needs by Disability Type

Learning Disabilities

Among students with learning disabilities, the following accommodations are identified as necessary in a general classroom or computer-based learning environment: (1) notetakers and/or audio-recorded class sessions; (2) captioned videos and films; (3) extra exam time and alternative testing arrangements; (4) visual, aural, and tactile instructional demonstrations; and (5) computers with speech output, spell-checkers, and grammar checkers (ACCESS STEM, 2006).

Mobility Impairments

For students with mobility impairments, computer access must include special input devices such as speech input, Morse code input, or alternative keyboards (ACCESS STEM, 2006).

Hearing Impairments

For students with hearing impairments, web access must provide: (1) interpreter or real-time captioning; (2) FM amplification systems; (3) captioned films; (4) use of visual aids; and (5) demonstration summaries (ACCESS STEM, 2006).

Blindness and Low Vision

For users who are blind, necessary accommodations include computers equipped with optical character readers, speech output, Braille screen displays, and/or Braille embossers. For those with low vision — defined as having some usable vision but being unable to read standard-size text, or experiencing field deficits such as limited peripheral or central vision — a computer equipped to enlarge screen characters and images is required (ACCESS STEM, 2006). This illustrates the wide scope of access challenges that must be addressed before disabled users can fully engage with web content.

The ACCESS STEM studies note that due to the multimedia nature of many web pages, combined with poor site design, disabled users may be unable to access the full range of resources the web offers. Specific problem areas include:

• Individuals with visual impairments may not be able to view graphics;
• Individuals with hearing impairments may not be able to hear audio output;
• Users with slow internet connections or older equipment may not be able to download large files; and
• People with learning disabilities, those who speak English as a second language, or younger-than-average users may have difficulty navigating poorly organized sites or sites with unclear directions (ACCESS STEM, 2006).

References

Krill, Paul (2002). W3C Promotes Web Access for Disabled. InfoWorld. Retrieved January 16, 2007.

Disability Web Access is Being Ignored (2004). The Register, April 14, 2004.

Nielsen, Jakob (1996). Accessible Design for Users with Disabilities. October 1996.

Disability Type (2006). ACCESS STEM — the Alliance for Access to Science, Technology, Engineering and Mathematics (Universal Design). University of Washington.

Web Pages (2006). ACCESS STEM — the Alliance for Access to Science, Technology, Engineering and Mathematics (Universal Design). University of Washington.

Software Compatibility: A Case Study on Assistive Technology, Accessible Course Software, and a Student with Low Vision (2006). ACCESS STEM — the Alliance for Access to Science, Technology, Engineering and Mathematics (Universal Design). University of Washington.

How Can Web Pages Be Made Accessible to Individuals Who Have Cognitive Disabilities? (2006). ACCESS STEM — the Alliance for Access to Science, Technology, Engineering and Mathematics (Universal Design). University of Washington.

UW Center for Technology and Disability Studies. Web Access Considerations under Section 504 & Title II, Office for Civil Rights, U.S. Department of Education, November 2002.