Website Evaluation: Accessibility

Royal National Institute of the Blind defines web Accessibility as follows:

Accessibility is the degree to which anyone can access and use a website using any web browsing technology. A fully accessible site is one that is designed to make use of the latest web technologies such as multimedia, while at the same time accommodating the needs of those who have difficulty with or are unable to use these technologies.

Why is Accessibility Important?

There's no excuse for not making a website Accessible... and there are some complelling reasons for making Accessibility a priority:

• The Disability Discrimination Act (DDA) 1995 makes web Accessibility a legal requirement for service providers
• Many of the tehniques used to improve Accessibility also improve Usability
• An accessible website is likely to be a search engine friendly website.

Accessibility Sub-elements

The BRAINBOX Website Evaluation breaks the Accessibility element down into three sub-elements:

• Valid HTML
• Structural Mark-up
• Alternatives
• What no Mouse?

Valid HTML

HTML - Hyper Text Mark-up Language - refers to the code that makes each the web page. HTML is subject to a set of rules: if these rules are followed to the letter, the webpage is said to consist of valid HTML.

In excess of 99% of webpages are composed of invalid HTML. Sighted uses are usually none the wiser: Internet Explorer has become adept at presenting web pages composed of invalid HTML. Other browsers - and especially those designed for disabled users - are far less forgiving.

Structural Mark-up

Web pages are usually more than unstrutured text: the text is usually broken into paragraphs, and there may be headings and lists.

Let's say we wanted to indicate a heading. HTML (HyperText Markup Language) gives us several ways to "mark-up" the heading text: we can make the text bigger, make it bold, change its colour. A sighted user would immediately recognise the text as a heading; a non-sighted - unable to see the distinctive formatting - would not.

What need to do is supplement this presentational mark-up with structural mark-up: we can use HTML to specifically mark the text as a headline.

Alternatives

Look at the last sentence from the RNIB definition:

A fully accessible site is one that is designed to make use of the latest web technologies such as multimedia, while at the same time accommodating the needs of those who have difficulty with or are unable to use these technologies.

In most cases, this means providing alternatives. A picture may be worth a thousand words... but non-sighted users cannot see the picture! HTML gives us a way of adding the words to the webpage. The sighted users get the picture, non-sighted users get the text.

• Images - in the form of ALT (alternative) text
• JavaScript - through the <noscript> tag
• Flash - with HTML equivalents
• Audio & video - by using written transcripts

What no Mouse?

Not everyone finds it easy - or even possible - to use a mouse. It should be possible to use most of the functionality of a website with just three keys (buttons): enter, tab and back.

By default, it's possible to tab from one link to the next. It's also possible to tab from one form element (such as a textbox or radio button) to the next.

Pop-ups should be avoided. By spawning a new browser window, the user is brought to a new "first page" and cannot, therefore, go pack to the previous page using the "back" button.

Caution!

We've just touched the surface here: there's much more that can - and should - be done to make a website Accessible.

IMPORTANT: A good score in this area is necessary though not sufficient for a high level of Accessibility.

Learn more about website Accessibility

Royal National Institute of the Blind Web Access Centre