Published by Rob Lambert,
Very few companies take web accessibility seriously but in a world that is increasingly moving online it is crucially important not to marginalise people who cannot interact with websites and applications.
Testing a site for accessibility is very simple in one respect, but very hard in another.
The accessibility of a site is typically judged against International compliance standards set out by W3C. Their guidelines essentially give three levels of compliance A, AA and AAA, although these guidelines are under continual review.
There are a number of automated tools which will check against the standards but you will still need a human eye to check the finer details and the nuances of compliance.
Achieving AAA compliance is really hard. I've only ever worked on one project that ever met AAA and we spent a lot of time and money on gaining the compliance - but it was worth it - we made the site accessible to the very people it was designed to serve.
How to test for accessibility
There are a number of tools on the market that check accessibility compliance. These tools will tell you whether you are compliant or not. They will list out improvements, recommendations and details of any failures.
These tools are pretty quick too providing rapid feedback against compliance, however, the answer you get will not tell you the whole truth. You need a human mind to verify the information.
In a very basic example you may have an image on the page. The image should have an “alt" attribute set so that people with screen readers can understand what the picture is.
If you don't have anything set for the “alt" tag an automated checker will warn you and explain you need to include text for this attribute.
Let’s say you have a picture of a red apple but you put an “alt" tag of “Brown Teddy Bear" and then run the scanner again. The scanner will give you a pass as you now have a value set for “alt" - it just so happens the value is incorrect. This is why you need human judgment.
The tools are incredibly useful and helpful but there is no substitute for human judgement, especially so when it comes to accessibility.
An automated tool will also not tell you whether the flow and logic makes sense to someone who cannot see the site and may not have prior knowledge of the page they are on, or even knowledge about what the site exists for.
In my experience there are very few people better at testing for accessibility than the very people who benefit from your accessible site.
It’s therefore important to consider outsourcing your testing to specialist accessibility testing companies or charities. They will offer you insights you will struggle to get through your own testing.
I once tested a site to AAA compliance according to the automated checkers and my own judgement, yet when I handed it over to an accessibility-testing expert from a charity I was stunned with how unusable it was. It was compliant, but it wasn't very easy or pleasing to use for this user.
Good accessibility testing needs human judgment and thinking. It cannot simply be automated. It requires trial and experimentation. It requires feedback from your target end users.
Saying that, the online tools are incredibly good at finding the obvious errors and compliance issues. Each year they become more refined, informative and powerful.
Whether you are aiming for compliance or not, an accessibility check will also point out some obvious flaws in the HTML and give you insight for areas to explore and test further.
This simplest way to check against W3C compliance is to use an automated checker in your browser. If your site is public facing you can also use an online checker by visiting their website and entering your URL in the site check.
Firefox accessibility extension - https://addons.mozilla.org/en-US/firefox/addon/accessibility-evaluation-toolb/
Tips on how best to describe the alt attribute - http://webdesign.about.com/od/beginningtutorials/a/aa122004.htm
Wave web accessibility checker -
Web accessibility checker -
If you’re interested in a career in Software Testing then check out my book Remaining Relevant And Employable (Tester’s Edition) - it’s packed full of ideas about writing good CVs, communicating your value to employers and doing well in an interview.