Shaun Mccran

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Web Accessibility 101 - What is it, and why do it?

In my developer life I've encountered many different clients who have a multitude of requirements for their web projects. One that is occuring more frequently is 'Accessibility'. Over the past year or so I've had to really delve into what this means for a website, and how it affects IT projects.

This is the first of a series of articles relating to Web Accessibility, breaking down how I understand each aspect of it, including things like best practice coding, testing, what your mark-up really tells impaired users and the general theory behind creating Accessible content. I'll also try and point out any tips I've uncovered to try and smooth out the, sometimes rock, path to validating a site as Accessibly compliant.

A loose definition

Before we really get into it the detail we probably attempt to define the term 'Accessibility'.

Breaking it down to a succinct definition would be something like,

"Accessibility defines the way you communicate how a user can interact, but not the behaviour of that interaction".

At a basic level this means that you have to communicate to a user how they can interact with your content, but you cannot dictate to them the method if that interaction. As an example you cannot force a user into a new window (target="_blank") as this is dictating the method of interaction, not the message contained within it.

This makes sense from a 'web etiquette' point of view when you consider that it is quite impolite to try and tell users what to do.

This isn't restricted to just code based interaction. It also includes the medium used in that communication, i.e. is the user using a regular web browser, a screen reader or any other form of viewer. Remember that your message can be communicated as text or audio.

Aims of Accessibility

That brings us nicely to the aims of Accessibility. Because we have now qualified the term Accessibility with the definition above we can identify what the aims of implementing Accessibility guidelines should achieve.
  • Allow enabled and disabled users the same level of communication. Do not exclude partially sighted or hard of hearing users due to their impediment.
  • Allow your users the ability to view your content in their chosen medium, it does not have to be exactly the same content, merely the same message
  • If you provide a user with a choice you have to provide enough information to allow them to make an informed decision about that choice
  • You must be able to accurately describe any choices (for example hyper links) outside of the context of the page, as an example if we have a hyper link with the text 'click here', outside the context of the surrounding content it means nothing, but if the same link were to say 'follow this link to view information about...' it would have the same meaning both within the page, and without.

This covers the basic concept of what Accessibility is, and the aims you should keep in mind when it is a factor of a web project. In the next article I'll discuss Accessibility standards, and go into depth about how you can actually start to make sure that your finished project will pass validation against those standards.

Comments (Comment Moderation is enabled. Your comment will not appear until approved.)
Martha Aldridge's Gravatar As well as adherence to WCAG standards it's worth knowing the status of the law with regard to web accessibility.

Technically Part III of the DDA (Disability Discrimination Act) came into force in October 1999 with the associated Code of Practise ( being released in 2002 meaning that the majority of public facing websites in the UK have been in breach of the law for years and are open to potential legal action and the RNIB (Royal National Institute for the Blind) has in fact taken steps with a number of large companies to get them to comply with the law so it's more than just being considerate to disabled users, there is a potential 'or else'.
# Posted By Martha Aldridge | 11/02/2011 13:36
Shaun McCran's Gravatar The problem with the DDA is that there are no solid guidelines. There is no definitive standard that they provide to actually guarantee your site is accessible. You just have to be able to prove that you've 'tried'. WCAG AAA correlates well, but still does not guarantee DDA compliance.
# Posted By Shaun McCran | 11/02/2011 14:54
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