What Should I Describe?

One of the big challenges a developer faces when trying to provide alternate textual descriptions for images is the question of exactly what to describe. This is a big question and one that, unfortunately, is usually moot. In truth, the area is a little fuzzy. This might not be very reassuring, but there you are. Some screen-reader users do want everything to be described, as much as possible, and others are happy as long as they get the information they need at any given time. More importantly, when a site has a specific function, many users are happy just to be able to complete the task they set out to do. They don't care if the graphics are described as long as they aren't missing any core functionality.

What I'll do here is outline some things I've learned over the years from doing user testing and expert evaluation of web sites. This has often involved working with blind screen-reader users, as well as users of other assistive technology (AT) devices. I will present the current thinking on accessibility best practices when it comes to HTML5, images, and other rich media. Then I'll leave you to make up your own mind!