An Introduction To Accessible Web Design

Technical Level:	Intermediate	Published:	23^rd November 2002
Author:	Nigel Peck	Last Updated:	-

Accessibility in Web Design addresses the issue of creating Web sites that are accessible to all users, regardless of physical ability or the way in which they are using the Internet.

In this article I will be introducing the concepts surrounding accessible Web Design, the current initiatives to increase the accessibility of Web sites and the guidelines that you can use to make your site more accessible.

Why Accessibility Is Important

Why aren't all Web sites accessible? You may be asking yourself why this issue exists and why all Web sites aren't already accessible to all users. There are a number of reasons that I will outline now.

Visually Disabled Users

Visually disabled users ranging from colour blind to fully blind have problems with images that do not provide a text description of what they show. Without a text description a user who can't see an image has no way of knowing what it is or what it represents.

These users also have problems understanding sites that are not logically built when "viewed" using a non-visual browser such as a screen reader. A screen reader is a Web Browser that reads Web sites out loud so as to make them accessible to visually disabled users. Often a Web site that looks nice visually will be a complete mess when it is listened to through a screen reader.

Hearing Disabilities

In a similar way to visually disabled users not having any way of understanding an image, users with hearing disabilities have no way of understanding information that is communicated with sound, unless an alternative is provided that does not use sound, such as a text description or an image.

Physical Disabilities

If you are not physically disabled, have you tried using a Web site without your mouse? Unless you were lucky with the site you chose then you probably found it very difficult. Physically disabled users are often incapable of using a mouse. Unless these users needs are taken into account when creating Web site navigation and input methods physically disabled users will sometimes find a Web site completely inaccessible.

Cognitive and Neurological Disabilities

Web sites can be complex, and finding the information we want can be difficult for the most able of us. This is not helped by sites that use an overly complex design, navigation that works differently on different pages (inconsistent) and distracting repetitive animation. All of these problems are compounded for users with Cognitive and Neurological Disabilities and this makes some sites completely inaccessible for them.

Beyond Disabilities

As we have seen, using the Internet if you have a disability can be a difficult task. By observing and understanding the guidelines for accessible Web Design a site can be produced that serves it's purpose and is accessible to all of it's users, not just those without disabilities.

But it doesn't stop there. Accessible Web Design has benefits for other users too. Let's see who else can benefit.

The following groups will benefit from following the guidelines for making your site accessible:

Users of mobile phones, Web-TV and kiosks,
Low bandwidth users,
Users in a noisy environment,
Users with "screen glare",
Users who are driving,
Users with a low literacy level,
Second-language access and
Users with different learning styles.

Dealing with accessibility issues also improves:

Page transmission and site maintenance,
Machine indexing of content and
Searching of content.

The Marketplace

There's another reason for making your site accessible (if you need any more). According to current figures disabled users currently make up around 10% to 20% of the population in most countries. Increase that for the amount of your users who fall into the categories listed above and you're looking at up to 30% of the market. If making your site accessible to 30% of the market doesn't persuade you that accessible Web Design is worth it then stop reading now.

The average age of the population in many countries is also increasing. Aging results in a number of accessibility issues including vision and hearing changes and changes in dexterity and memory. If your market includes a significant number of elderly users then you can increase that 30% to a much larger percentage of users who will reap the benefits of accessible Web Design.

Legal Requirement

For certain Web sites, addressing accessibility can be a legal requirement. This is usually for government sites but can affect others, every UK Web site must be accesbile under the Disability Discrimination Act. For more information on the requirements in different countries see the W3C page Policies Relating to Web Accessibility.

Accessibility Initiatives

A number of groups around the world are working on increasing awareness and helping authors of accessible Web sites. These include the World Wide Web Consortium (W3C), the US Government and CAST/Watchfire. We will be looking at what each of these groups has done in more detail starting with the W3C.

Web Accessibility Initiative

Since 1999 the World Wide Web Consortium (W3C) (the organisation that creates the standards for the web) has been working on its "Web Accessibility Initiative" or WAI. The official mission of this initiative is:

The World Wide Web Consortium's (W3C) commitment to lead the Web to its full potential includes promoting a high degree of usability for people with disabilities. WAI, in coordination with organizations around the world, pursues accessibility of the Web through five primary areas of work: technology, guidelines, tools, education and outreach, and research and development.

The result of this initiative so far has been three sets of guidelines:

The Web Content guidelines are designed to show Web site authors how to make their site accessible. The Authoring Tool guidelines are for people writing programs that can be used to create Web sites. The User Agent guidelines are for people who are creating Web browsers.

I will not be discussing Authoring Tool or User Agent guidelines any further as they are not the topic of this discussion and are only relevant to authors of those programs.

Web Content Accessibility Guidelines 1.0

The Web Content Accessibility Guidelines or WCAG became a W3C recommendation on the 5th of May 1999 (becoming a W3C recommendation is an extremely tough and long process).

It's purpose is to explain accessible use of Web technologies for those who create Web sites. This is achieved through 14 guidelines with a total of 60 checkpoints to be followed to make sure a site is accessible.

To accommodate the varying levels of effort people are willing to put in to making their sites accessible the checkpoints are broken down into 3 different priority levels. The specification lays out the three priority levels as follows:

[Priority 1]: A Web content developer must satisfy this checkpoint. Otherwise, one or more groups will find it impossible to access information in the document. Satisfying this checkpoint is a basic requirement for some groups to be able to use Web documents.
[Priority 2]: A Web content developer should satisfy this checkpoint. Otherwise, one or more groups will find it difficult to access information in the document. Satisfying this checkpoint will remove significant barriers to accessing Web documents.
[Priority 3]: A Web content developer may address this checkpoint. Otherwise, one or more groups will find it somewhat difficult to access information in the document. Satisfying this checkpoint will improve access to Web documents.

For those who take the time to produce pages that conform to any of the above priority levels there is a matching set of conformance levels:

Level 'A': All Priority 1 checkpoints are satisfied.
Level 'Double-A': All Priority 1 and 2 checkpoints are satisfied.
Level 'Triple-A': All Priority 1, 2, and 3 checkpoints are satisfied

Pages, sites or portions of sites that conform to one of the three levels may then display a logo, linked to the appropriate W3C explanation of the claim:

Level 'A'
Level 'Double-A'
Level 'Triple-A'

For full details of the conformance logos see the W3C WCAG Conformance Logos. Alternatively, conformance can be specified through a text explanation such as:

This page conforms to W3C's "Web Content Accessibility Guidelines 1.0", available at http://www.w3.org/TR/1999/WAI-WEBCONTENT-19990505, level Double-A.

The text must specify:

The guidelines title: "Web Content Accessibility Guidelines 1.0"
The guidelines URI: http://www.w3.org/TR/1999/WAI-WEBCONTENT-19990505
The conformance level satisfied: "A", "Double-A", or "Triple-A".
The scope covered by the claim (e.g., page, site, or defined portion of a site.).

The Web Content Accessibility Guidelines were developed by the Web Content Accessibility Guidelines Working Group (WCAG WG). The following W3C pages will be useful to you if you would like to produce pages that conform to WCAG 1.0:

The US Government - Section 508

The US Government has endorsed the W3C Web Content Accessibility Guidelines by forcing all federal Web sites and sites that are under a federal contract to comply with the guidelines. More information can be obtained from Section 508.

Bobby

While it is possible to read the Web Content Accessibility Guidelines and build your site to comply, wouldn't it be easier if there were a tool to test it for you? You've guessed it, there is, a product called Bobby was produced by a non-profit organisation called CAST in order to test sites to be sure they complied with the guidelines, it is also aware of the conformance levels and will tell you which level you are at (if any).

In December 2001 Bobby also began supporting Section 508, which makes it the most complete accessibility tester available. In July 2002 Bobby was purchased by a company called Watchfire, who now look after the product.

Bobby has it's own set of logos that work in much the same ways as the W3C logos:

Level 'A'
Level 'Double-A'
Level 'Triple-A'

Or for Section 508 compliance approved by Bobby:

You can use bobby in two ways. If you only want to test a few pages here and there it is available as a free on-line tool at https://bobby.watchfire.com/ and works in much the same way as the W3C HTML validator (if you've used it). You enter the URL of the document you want to check and then you receive a report of where you comply and where you don't. Because of the nature of the accessibility guidelines it is not possible to check everything through a program so you will still have to check some things yourself, Bobby tells you what to check.

If you want to check a lot of pages then the on-line tool has its limitations (you can only do a small number of checks per hour) so you would probably be best purchasing the downloadable version so that you can check as many pages as you like. At the time of this writing (November 2002) the price is $99.

A nice feature of Bobby is that for every guideline advice is readily available on how to make your document comply and why it is import for accessibility.

Over to you

That's the end of this introduction to accessible Web Design. For more information the urls given in the article should give you a good start (listed below). Have fun making your sites accessible!

Further Information

The following sites were mentioned in the article (in document order):

Looking for Assistance?

Are you looking for professional assistance with web accessibility? Our directory of providers can be a good place to start.