About web accessibility

An updated version of a talk I gave to a members' meeting of CASE (Computing Assistance, Support & Education) in 1999

Interoperability & disabled access

HTML is wonderful: it allows us to access content regardless of platform. When the WWW started, it opened a new window on the world. This was particularly so for disabled users. (I write as a person with mobility problems who can now access information from home that I physically couldn't deal with in libraries.) It must have been an especially wonderful time for vision-impaired web users. Speech browsers or screen readers transmitted the content of the simple text-based early web pages with ease.

With the influx of businesses onto the web, the emphasis shifted to graphical, brochure-like pages. The use of image maps for navigation became widespread. For those not accessing the WWW primarily in visual mode - vision-impaired people, people who turn graphics off because of slow machines or slow links, people using palmtops, or voice browsers in their cars - many pages became unusable.

This didn't and doesn't have to happen. There are methods of retaining accessibility - making sure each image has an ALT tag, for example, and providing text alternatives to image maps. But web authors have to be informed and motivated about accessibility - and they should also bear in mind that laws are now prescribing it!

Other major stumbling blocks to accessibility include:


  1. Frames violate the principle of platform independence
    (everything is designed to accommodate only browsers running on big-screen graphical displays)
  2. Framesets are not addressable
    (the URL doesn't change as you navigate through a site - a bookmarking problem)
  3. Frames are totally incompatible with some browsers

- Summary of What's wrong with frames? by Arnoud "Galactus" Engelfriet (Web Design Group)

Furthermore, frames can prevent search engines from indexing your site.

The FONT tag

"The font tag is a hindrance to communication over the World Wide Web because it makes too many assumptions about the user's system, browser, and configuration."

- Warren Steel, What's wrong with the FONT element?

Using tables for layout

"Tables should not be used purely as a means to layout document content as this may present problems when rendering to non-visual media. Additionally, when used with graphics, these tables may force users to scroll horizontally to view a table designed on a system with a larger display. To minimize these problems, authors should use style sheets to control layout rather than tables."

- W3C, HTML 4.0 Specification - Tables

As with frames, a further hazard of tables is that they mask your content from search engines.


Web pages are very different from printed pages. One critical difference is that they're not really "pages" at all. Content is fluid on the Web, and the Web is different for every user. As web authors, we'd be wise to abandon assumptions about our visitors - that they're bound to be using a well-known browser, that they're viewing in a full-sized window, that they're viewing at all - and work towards broad accessibility.

"Anything that is a great print design is likely to be a lousy web design."

- Jakob Nielsen, Print Design vs. Web Design
(Alertbox Jan 1999)

"...it is often the case that design rules that may have been intended to help users with disabilities end up being of benefit to all users."

- Jakob Nielsen, Accessible Design for Users With Disabilities
(Alertbox Oct. 1996)

Valid HTML + Stylesheets - a solution?

W3C (The World Wide Web Consortium) develops common protocols that promote the evolution of the Web and ensure its interoperability. Current protocols are designed to improve accessibility on all platforms and displays, and to disabled users.

W3C recommends stylesheets for controlling the presentation (fonts, alignment, colours, etc) of documents. Stylesheets are separate from hypertext markup language (HTML) which is used to mark up headings, paragraphs, lists, hypertext links, and other structural parts of documents.

Using stylesheets and valid HTML 4.0:

"...you are more likely to end up with pages that are easy to maintain, look acceptable to users regardless of the browser they are using, and can be accessed by the many Web users with disabilities."

- From W3C's Guidelines for Authoring

The use of stylesheets still poses some problems, due to patchy implementation. Fortunately, the combination of stylesheets and valid HTML "degrades gracefully". Someone using a non-stylesheet-capable browser will get a very plain web page. But they'll get all the content, and all the pictures apart from background graphics. They won't lose any of it.

Useful Links

Web Standards


Some Australian pages re accessibility

Specific problems

Some general authoring resources

Cascading Stylesheets (CSS)

Checking services

Page created 13 July 2002; last updated 22 December 2012