The problem with automated accessibility testing tools
An automated accessibility tool is a piece of software which can test a web page, or even an entire website, for accessibility. Automated accessibility tools are useful because they can save you a huge amount of time. Don't want to check images for alt text on each and every page on your website? Run the site through an automated tester and it'll do it all for you!
Automated accessibility testing tools have been around for a long time and have historically been a useful way of checking websites for accessibility. Bobby, one of the first and most well-known automated accessibility testing tools, is now almost 10 years, and although is no longer freely available, plenty of other free tools such as WebXact1 and Wave2 do exist.
But are these tools a little too good to be true? Can you test a website for accessibility so easily? Unfortunately the answer is a resounding no. There are a number of underlying problems associated with using just automated tools to test for accessibility:
Literal interpretation of guidelines
Any automated accessibility testing tool, being a piece of software, doesn't have very much in the way of common sense. It will interpret each and every accessibility guideline literally, without bearing any other thought to what else is on the page.
The definition of the word guideline, according to Dictionary.com, is “a rule or principle that provides guidance to appropriate behaviour”. A guideline simply offers guidance to what the best practice is - it shouldn't just be applied without regard to other factors.
For example, one of the W3C accessibility guidelines states that a table summary should be provided for all tables. (This summary doesn't appear on the screen, but it's read aloud to screen reader users before reading through the table content.) Table summaries are useful as they tell screen reader users what to expect in the table. However, there may be a heading directly before the table and it describes what the table is about. In this instance, this summary is essentially useless as it will just repeat what the previous heading said.
Can't check any content issues
The way that content is structured both on the page and across the website is a massive part of accessibility. A website may be perfectly coded and conform to the highest coding standards. If its content is poorly structured though, the site will prove difficult to impossible for some special needs web users.
There are a number of important accessible content considerations, none of which automated accessibility testing tools can check for. Some of these important considerations include:
* Front-loading content so that each paragraph begins with the conclusion
* Ensuring content has been broken down into manageable chunks with descriptive sub-headings
* Using lists wherever appropriate
* Ensuring that plain and simple language is used
Can't check many coding issues
The vast number of accessibility guidelines tend to be related to how the site is coded. Automated accessibility testing tools are unfortunately unable to test for many of these too. Examples of HTML-related accessibility considerations which these tools can't check for include:
* Ensuring that text is real text and isn't embedded within images
* Making sure that the site functions without the use of JavaScript or Flash
* Providing equivalent text links if using server-side image maps
* Ensuring that the structure within the HTML reflects the visual appearance (e.g. headings are labelled as headings within the HTML code)
Outdated guidelines are used
Automated accessibility testing tools generally use the W3C accessibility guidelines, which by now are over five years old. As such, a number of these guidelines are outdated and don't apply anymore. In fact, some of them are now thought to hinder accessibility rather than help, so it's best to totally ignore these outdated guidelines.
For example, an automated accessibility testing tool will probably insist that form items contain default place holding text. It may also insist that links need to be separated by non-link text. Neither of these guidelines are relevant anymore and their implementation could make accessibility worse rather than better. |