Another issue with AJAX is how the application interface is updated. When updates to the interface occur, it may not be visually apparent that a change has occurred. The problem is even more troublesome for screen reader users. Screen readers typically read in a linear fashion. When changes happen in the interface, the screen reader user may not be aware of the change and the new content will likely not be read.

In short, to allow dynamic interface changes to be accessible, the application must alert the user that a change has occurred, allow direct access to the new content, and then allow continued functionality of the web application. This process, while difficult to achieve, especially for screen reader users, is possible to achieve in many AJAX applications.

Improving accessibility of AJAX forms Fortunately there are some things we can do to increase accessbility of AJAX forms. Here are my recommendations: Inform the user at the top of the form that it requires javascript or detect javascript automatically and warn the user when it isn’t available. If the form has many fields you will spare your users a lot of frustration. Everyone hates filling out a form just to find out that they can’t submit it. Inform the user that the page is updated dynamically. This is especially important for screen reader users and will help them decide when to trigger a re-read of the page. Make it possible to recieve an alert when information was updated. This may not be practically possible depending on the complexity of your form but will help a screen reader user a lot. Alert boxes are read by the screen reader and are usually displayed together with a sound. The checkbox should be displayed so it is clear that it is not part of the original form. Highlight recently updated areas for a short period of time. This will help sighted users understand what just happened. The nice folks over at 37signals have dubbed this “The Yellow Fade Technique” but you can use any colour you like. Check out Adam Michela’s code for another way of providing the fade.