Accessible Webpages


Contents


Introduction

An 'accessible' webpage is one where the information within it is wholly and easily receivable by its readers regardless of the means by which they receive it.

In this context it is important to bear in mind that the web was devised to be a 'universal' medium [1] - one which can be accessed in a wide variety of ways according to the individual requirements of each reader.

To achieve 'universal accessibility', authors have to be aware of the twin factors governing accessible page design - conformance to technical standards and attention to readers' needs.

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Technical Issues

Conformance to technical standards is a relatively simple matter. These define the structure and various elements of webpage markup (HTML) and full documentation is readily available, free of charge, on the web. [2]

Once you have created your pages and put them on your server, it's a simple matter to see if they conform - this is known as 'validating' them. You submit their URLs (web page addresses) to an online validator [3] and read the report which comes back. If there are errors, you fix them and resubmit the URL until the page passes.

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Accessibility Barriers

Once your pages validate, you will know that they will be receivable in the technical sense. However, you won't yet know if they contain other, more subtle barriers to accessibility which the technical standards cannot provide for. Again, online help is at hand at W3C, where the Web Accessibility Initiative publishes guidelines for authors. [4]

As a quick check for some of these barriers, you can submit your URLs to 'Bobby' [5], which will respond with a report listing problem areas, and a useful assessment of page loading speed.

It's worth listing some of the different browsing situations readers can find themselves in. An accessible webpage has to be meaningful in all these situations and more:

The aim of an accessible page is to maximise the value of the information that each of these readers receives. With such a variety, that's quite a tall order, but with care it can be done.

Here are some of the more commonly encountered barriers to accessibility which may pass unnoticed by the validator:

The standards now require that alternative texts that describe the meaning of inline images be provided for the benefit of text-only readers. Where these are missing or ill-thought-out, that information is destroyed or becomes misleading. [6]

Many sites provide images which are too large for quick downloading. It's a fact of life that many readers will refuse to wait and will simply go elsewhere. Often they will never return. It is possible to process images so that their file size is small, yet without impairing legibility.

More often than not, misusing or omitting certain required HTML elements from webpages has serious accessibility consequences. This is particularly prevalent in pages containing tables [7], or in multi-frame pages. [8]

Using proprietary extensions to HTML without great care will almost certainly cause difficulties for some readers.

Using proprietary script languages for essential page functions will restrict access to those users who have the necessary software, and who allow, or are allowed to use them.

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Design Issues

Designing web sites with full accessibility in mind does not (as is sometimes misleadingly claimed) require additional design work, nor require different versions of web pages for different viewing situations. On the contrary: experienced web designers report that designing to one, published, interworking specification and to clear accessibility guidelines is easier and more economical than trying to design specifically for several different vendors' browsers, and then trying to rectify the problems on a piecemeal basis afterwards.

Many of the techniques that are used on the web in an attempt to impose a specific graphic design on the reader are potentially hostile to accessibility considerations.

The process of 'designing' a web page is not - or it should not be - at all comparable to designing, say, a magazine article, or printed advertisement, which is going to be printed in one size on one kind of paper with one set of colour options, and in the hope of attracting the attention of a reader whose thoughts are elsewhere. A web page will only be seen by a reader who has deliberately sought it out and keen to have the information which it offers; it will be displayed in many different ways according to the reader's situation, and any 'design' procedure that fails to take this into account is misguided.

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Who Must Provide Accessible Websites?

If you are responsible for a publicly-funded website you have a moral duty to make your site accessible to all who fund you. You cannot duck this issue.

If you are a responsible for a commercial website you may not have such a strict duty, assuming that your firm is not receiving public support for providing it. However, if you make your site inaccessible, you may be turning away many potential customers. If your boss found out that you were doing so, how would s/he react?

If you're simply providing a private home web site then it's entirely up to you what you do with it. Think about this though - many private sites do take the trouble to be accessible, and enjoy the satisfaction of knowing that it's appreciated.

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Why is Web Accessibility Important?

The web is an 'enabling' medium, and may in the evolution of things come to be seen to be as important as the printing press was in its day. For the first time ever, people from all walks of life from all over the world are able to set out their ideas and knowledge for the perusal of others in a way that was never possible before. Making web pages easily accessible will help this process to flourish to the ultimate benefit of all.

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References:

[1]
"The concept of the web is of universal readership. If you publish a document on the web, it is important that anyone who has access to it can read it and link to it."
- Tim Berners-Lee (who invented the web)
"Anyone who slaps a 'this page is best viewed with Browser X' label on a Web page appears to be yearning for the bad old days, before the Web, when you had very little chance of reading a document written on another computer, another word processor, or another network."
- Tim Berners-Lee in Technology Review, July 1996
[2]
The Web Design Group at http://www.htmlhelp.com/.
[3]
The W3C's Online Validator at http://validator.w3.org/.
[4]
The Web Accessibility Initiative's Author Guidelines at http://www.w3.org/TR/WD-WAI-PAGEAUTH.
[5]
'Bobby' The Online Accessibility Checker at http://www.cast.org/bobby/.
[6]
Alan Flavell's essay on ALTernative Texts, at http://ppewww.ph.gla.ac.uk/%7Eflavell/alt/alt-text.html.
[7]
Alan Flavell's essay on TABLEs at http://ppewww.ph.gla.ac.uk/%7Eflavell/tablejob.html.
[8]
The Web Design Group's FRAMEs FAQ at http://www.htmlhelp.com/design/frames/faq/.

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Iain
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