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Understanding Web accessibility

Posted 2003.04.18

Understanding Web accessibility


This article first appeared in the Journal of Volunteer Administration, Volume 21, Nº 1, 2003, pp. 36–39, published by the Association for Volunteer Administration.


People with disabilities can and do surf the Web, often with the use of adaptive technology that compensates for particular disabilities. But for Web sites to be reasonably accessible, Web authors have to take certain care in the way they create pages. The article explains the basics of Web accessibility; explores the range of disability groups involved, with population statistics; and provides references for accessible Web authoring.


All the features of the World Wide Web that make it appealing to nondisabled persons – the enormous range of information, the unfiltered opinions published by average people, the self-serve shopping, and more – also make the Web appealing to people with disabilities. However, statistics show that disabled people have a lower Web usage than people without disabilities. Volunteer administrators can increase disabled people’s participation in their organizations’ Web sites by “authoring” – that is, coding, writing, designing, and publishing – those sites according to standards that are generally easy and inexpensive to meet. By doing so, Web sites will be much more accessible to many disabled people.

How many disabled people are online?

The available figures on numbers of people with disabilities online are not very thorough, but they provide a reasonable indication.

Gerber and Kirchner’s study (2001) summarizes the available data on visual impairment and computer and Internet use. They report that, in the United States, “[t]he total number of people ages 15 and older with any ‘limitation in seeing’ who report they have access to the Internet is just over 1.5 million (1,549,000).... [A]bout 196,000 people with a ‘severe’ limitation in seeing have access to the Internet, and about 102,000 persons with a severe limitation in seeing use a computer on a regular basis.”

People with other disabilities use the Web. The Survey on Income and Program Participation or SIPP (Bureau of the Census, 2000) estimated the number of people with certain disabilities and “access” to the Internet. What “access” means is ambiguous, though, by the researchers’ own admission: It could simply mean a computer exists in the home or workplace that can be connected to the Internet, or it could refer to active Internet use by the person in question. Even with this ambiguity, the figures are still helpful:

By contrast, in the same survey, 56.7% of nondisabled people have Internet access. The disparity is considerable.

How do people with disabilities use computers?

Even given the lower participation rate among people with disabilities, disabled groups are, in fact, online. But how do people with disabilities use computers?

Some disabilities, like hearing impairment, may require no modifications at all; people with those disabilities use the same equipment as nondisabled people. However, adaptive technology is commonly used by people with disabilities to customize equipment for their disability.

A person with limited use of the hands or arms may require a different input method, like a large trackball, a modified keyboard, or software that works with one or more switches that can emulate a keyboard or mouse. A person with a modest visual impairment may use screen-magnification software that blows up the size of the entire display. Someone with a more severe visual impairment may use a screen reader – software that reads text, menus, icons, and everything else that is visible in a computer’s interface out loud in a synthesized voice.

Which disabilities are most affected?

When it comes to accessible Web development, some disability groups need more attention than others. Blind and visually-impaired people top the list for the simple reason that the Web is a visual medium. Next on the list, and somewhat neglected, are people with mobility impairments, who find it difficult to move around complicated Web pages with dozens of links and other manipulable items.

Other disability groups are less likely to require accessibility – either because there is little on the Web that pertains to their disability (e.g., soundtracks are uncommon on the Web, so deaf and hard-of-hearing people do not face enormous barriers) or because the disability cannot be substantially accommodated without a rethinking of the Web as we know it (as with cognitive disabilities like dyslexia).

What is accessibility?

The term accessibility can be understood to mean accommodating characteristics a person cannot change (Clark 2003). A blind person cannot stop being blind when confronted with a visual Web page, for example, so blindness becomes an issue that requires accommodation.

Accessible vs. inaccessible pages

It is impossible to declare a certain Web page “accessible” or “inaccessible” for the simple reason that there are too many provisos involved. Accessible to which groups? Under what conditions? Using which adaptive technology, if any?

However, it is possible to design Web pages according to published criteria, which, if implemented intelligently, will result in improved access by specific disability groups. The reference for Web accessibility standards is the Web Content Accessibility Guidelines (WCAG), published by the Web Accessibility Initiative (1999) of the World Wide Web Consortium.

The WCAG provides a list of recommended practices for Web developers at three severity or importance levels. Priority 1 guidelines, if met, are “a basic requirement for some groups to be able to use Web documents.” Priority 2 requirements, if met, “will remove significant barriers to accessing Web documents.” Finally, Priority 3 requirements, if met, “will improve access to Web documents.”

The three priority levels are standards that Web authors “must,” “should,” and “may” follow, respectively. The hierarchy suggested by the three priority levels has a strong basis in practical fact. A Web page that meets Priority 1 guidelines probably will be significantly easier to use for a wide range of disabled people, while Priorities 2 and 3 offer decreasing returns.

Priority 1 guidelines are generally easy to meet. Some example requirements:

Adding accessibility to workflow

For volunteer organizations, it might not be difficult to add accessible Web design to the workflow of day-to-day Web publishing. Your site is probably based on templates that are reused from page to page; if you update those templates to meet the Web Content Accessibility Guidelines, you accomplish a great deal in a single stroke. If your organization publishes more text than images, meeting Priority 1 guidelines is almost automatic most of the time, since text is usually accessible to many disabled groups

A few difficulties can be foreseen, though. Some Web-design software makes it very difficult to control the exact contents of the HTML it produces. Your pages become much larger and more complex than they actually need to be – and harder to update. (It may be difficult to publish a table with correct row and column headers, for example.) Or you may be unable to alter the underlying HTML of your site, being limited to adding new content only. Or, in a more advanced case, your budget may allow you to post multimedia on your site, but you may not have allocated a budget to add captions (for deaf viewers) and audio descriptions (an ongoing narration track for blind viewers that explains what’s happening in the video image).

However, those problems can often be overcome – e.g., some newer authoring programs produce compact, easily-updated HTML but are free or low-cost, and it is also possible to use free or low-cost tools to make multimedia accessible. Even if your organization cannot do everything possible to improve its Web accessibility, it’s always possible to do something.


Accessible Web development is generally not difficult or expensive and can benefit large numbers of people with disabilities who are online. Publishing Web sites that meet accessibility guidelines is an easy way for volunteer administrators to significantly reduce barriers to participation by people with disabilities.


Bureau of the Census (2000). “Internet access, computer use, and disability status: 1999.” Survey of Income and Program Participation (1999, unpublished tabulation). Washington, DC: Author.

Clark, Joe (2003). Building Accessible Websites. Indianapolis: New Riders. 6.

Ferg, Stephen (2002). Techniques for Accessible HTML Tables. Viewed 2002-12-31.

Gerber, Elaine, and Corinne Kirchner (2001). “Who’s Surfing? Internet Access and Computer Use by Visually Impaired Youth and Adults.” Journal of Visual Impairment & Blindness, 95(3), 176–181; . Viewed 2002-12-29.

Web Accessibility Initiative (1999). Web Content Accessibility Guidelines 1.0. Viewed 2002-12-29.