Technical Tips
Making websites more accessible to persons with disabilities (part I)

David Mertz, Ph.D.
August 2000

Tips on making your web pages and web sites disabled- accessible. Part I gives a general introduction to disability issues, and discusses the structural markup at the heart of HTML. Part II discusses specific HTML coding "gotchas" that make your pages unnecessarily difficult for vision and mobility limited people to use; part II also provides an overview of free tools to use in evaluating and improving the accessibility of your site.

Issues To Start Thinking About

Making your web site friendly to--or at least usable by--persons with disabilities expands yours audience; in some cases doing so might be mandated by law; and in every case, it is the right thing to do. Moreover, many of the techniques that go into making more disabled-accessible web pages wind up making web pages that are just plain better for everyone.

People have a variety of differing abilities to operate computers, and corresponding to these abilities (as well as to their ability to pay for technologies) disabled persons employ a variety of tools and techniques to mediate their access to the internet. Blind or seriously visually impaired people might use screen readers or brail readers to translate pages. People with other visual impairements might use screen magnifiers, or might be unable to make color distinctions. People with neurological and mobility limitations might have difficulty operating a mouse and/or a keyboard; they might use special keyboards or spoken input to replace these. People with hearing loss or deafness will not be able to use sounds included in pages. And yet, all of these people are able to comprehend and utilize many types of information and functionality on the web... and probably most of the actual information on your web site if you take the effort to allow them to.

There should be no reason why persons with disabilities should not be able to read about your organization or company, order products from you, complete forms and launch server processes (of the sort you implement), or participate in discussion areas (if you have them). If your site closes these options to persons with disabilities, the only reason is bad design on your part.

The Very Good Design Of Html

HTML was designed as a means for structural markup of hypertextual content. It was really not designed as a way of doing desktop publishing or graphic design, despite the number of tools that have tried to shoe-horn HTML into those functions. If you stick to the intention of HTML when you create HTML, you are probably 90% of the way toward making your site accessible. For example, any technical means of rendering a web page will have some reasonable way of conveying concepts like: "this is a paragraph", "this is a hyperlink", "this is a secondary heading." The basic semantic of structural elements will be rendered by speech synthesizers, or by brail, or by three-inch tall onscreen fonts. What might not be rendered in a manner appropriate for a header is something that you try to make look like a header by putting it in a certain font size, face, color and style, but without actually marking it with an <h2> tag or the like. Fortunately, style sheets let you do both things at once: mark something as an HTML header, but recommend that the browser render the header in a certain way (but only if it make sense for the browser and user).

On the input side of things, HTML forms are equally well designed. Every entry field identifies itself by the type of information it enters, and reasonable means can be used to enter these abstract types of information without a mouse, or with special keyboards, or with voice recognition. The only time that entry is likely to exclude disabled users is when you go a long way out of the way to perform entry in ways that avoid the simple HTML form methods--such as Javascript tricks, Java entry applications where they are not needed, or special plugins (which are also likely to be platform restricted). For example, I have found an annoying habit of some web-sites to have forms with a graphical "Submit" button that cannot be reached in tab order, but only with a mouse-click (it takes some extra work to program this in the first place!). This needlessly excludes the blind and those who cannot use a mouse--as well as annoys sighted typists like me who prefer to keep my hands on the keyboard.

Quite aside from disabled users, a wide variety of new ways of viewing web pages are growing in popularity. PDA's, cell-phones, pagers, car-dashboard displays, embedded devices, kiosks, and other types of unconventional web-display machines are likely not to support the same display, plugin and input assumptions you might make for conventional PCs. A lot of the issues relevant to new devices are surprisingly similar to disability issues. And good HTML works everywhere.


An excellent starting point for many accessibility issues is The Disability Rights Activist. This site provides links to laws, guidelines, and downloadable software:

Many high-quality detailed suggestions for accessible web site design can be found at the Web Content Accessibility Guidelines 1.0 (W3C Recommendation 5-May-1999):

The law surrounding mandated web site accessibility are complex and differ between countries. In the United States, the main law governing this is the Americans with Disabilities Act (ADA) of 1990. Links to many national laws and related pages can be found at:

About The Author

Picture of Author David Mertz has been consumed with ressentiment since the introduction of the <blink> tag in Netscape 2.0. David may be reached at [email protected]; his life pored over at Suggestions and recommendations on this, past, or future, columns are welcomed.