What are the key components of web accessibility?

问题:

I understand that some countries have laws regarding website accessibility. In general, what are the minimum requirements that a website must meet to be accessible, regardless of country? Or, in lieu of minimum requirements, what are some specific things that websites should have to make the accessible?

回答1:

W3C publishes Web Content Accessibility Guidelines:

http://www.w3.org/TR/WAI-WEBCONTENT/

If you want a quick summary list, look for the yellow-highlighted lines in that document. Each guideline is also broken down into specific requirements ("checkpoints") in one of three priorities - to claim any kind of accessibility under this scheme you must satisfy all priority 1 checkpoints, but they're "necessary" rather than "sufficient" conditions.

Looking at your pages in lynx is also a good measure - if it won't render in text, chances are good that a screen reader will have a difficult time of it too.

回答2:

I recommend A-prompt for testing of Accessibility. It is free and it can really help.

I also recommend Mark Pilgrim's online text - Dive into Accessibility.

回答3:

It's not a binary question, and there's no silver bullet. Making sure you follow at least the basics of WCAG and testing in a couple of screen readers and without the mouse will probably be the most effective use of your time. If at all possible, test with real people with real disabilities, they have a perspective that is hard for fully-abled people to attain.

回答4:

Well, obviously the law in different countries varies vastly. In the UK, for example, we don't have any specific web-accessibility laws, but no service is allowed to discriminate against someone with a sight or hearing impediment, insofar as it relates to functionality.

In light of this, a simplistic way to design would be to ensure that your website is readable by screen-readers, can be tabbed through successfully and in a logical order, and allows the scaling of screen elements (including images and font sizes) correctly for those who require web-pages to be magnified.

In addition, your website should have functionality fall-backs in place for any JavaScript and Flash, such that if they were turned off (such as is the case in many screen readers) all functionality is still usable. Don't rely on WAI-ARIA for JavaScript accessibility, as it isn't standardised, and it isn't widely supported.

Of course, this doesn't necessarily cover every possible law, but it's a good starting point. If your website meets the above 'criteria', you're likely to have a good level of accessibility. There is a test for accessibility, of sorts, following WCAG but it's by no means 'conclusive' for what is an acceptable level of accessibility in each individual country.