What is accessibility?

One of my most enlightening experience at a previous job was learning more about web accessibility. At first the word "accessibility" may conjure images of people in wheelchairs needing ramps, rather than stairs, to enter buildings. This isn't so far off the mark in terms of web design.

Accessibility certainly deals with making websites that work for individuals with impairments that might make websites otherwise difficult to use. These can include:

• Visual Impairment - Note that this covers a wide range, from the completely blind (who use screen readers to have content read to them) to those with poor eyesight (who can see but need larger text and clear imagery) to those with color blindness (who may have difficult seeing certain contrasting colors, such as red text on a green background).
• Hearing Impairment - One might think this is not a problem on the web, but as video and sound are increasingly used, some sites have entire introductions and "avatars" that use audio to provide instructions and content -- without a text component, the hearing impaired are lost.
• Motor Skill Impairment - I don't know the technical term for this one, but it's important to remember that not everyone uses a mouse, and not everyone who uses a mouse has the dexterity to easily click on a link if it is just a few pixels in size.
  

The funny thing about designing websites with all of the above in mind is that you generally are improving usability for non-impaired visitors as well. Some people with fine vision may simply prefer larger text for reading, and good visual contrast makes a site easier on the eyes for everyone. Similarly, someone may not be hearing impaired but may be browsing your site in an environment where they can't have sound turned on (such as at work or at a library) -- making sure your navigation and content is available as text helps here, and can also help those who may not be fully fluent in your language and find it easier to read text. And of course, we've probably all been in situations where we've moved our mouse through a set of complicated drop-down menus only to get frustrated as moving 1 pixel outside the target area makes the whole menu disappear -- that doesn't require any impairment to be annoying.

There are also behind-the-scenes benefits -- websites coded with accessibility in mind can often place higher in search engines, as semantic markup (for example, labeling your headers as headers rather than just regular text with fancy font formatting), image text replacement (that is, whenever your graphics have text in them, the text should be written into the code as well), and proper usage of "alt" and "title" tags will help the search engine find your content and mark it as relevant.

It's also important to keep in mind that many web technologies -- such as JavaScript and Flash -- are not enabled or available to some users (the most notable recent example being the iPhone's lack of Flash support). The concept of "degrading gracefully" has become an important one -- essentially meaning that should these technologies be turned off, your site content should still display in a readable (and hopefully visually pleasing) manner.

I do not consider myself an expert in accessibility but it is certainly something I keep in mind as I design sites, and with each new project I try to implement new learnings. I think it's important to share this concept, however, as many people have never even heard of or thought about website accessibility. Having this knowledge in the back of your mind, even if you don't necessarily know 100% what its implications are, can help in the decision-making process during design. Accessibility issues may only be strictly necessary for a rather small minority of visitors, but designing with them in mind usually has a positive impact for everyone browsing your site.