2.2 AJAX
AJAX which stands for Asynchronous JavaScript and XML has allowed designers and programmers the functionality to create desktop-like web based applications on the internet. AJAX is not a new technology but a method of using existing technologies together. As AJAX is not itself a standard there are numerous ways of designing an AJAX application.
The principles of AJAX allow content on a web page to be altered by sending requests to a server without the need of the whole page reloading. This can provide a smoother interaction between a user and a web based application as there is less time spent waiting for entire pages to reload (Ritchie, 2007). There have been several methods used to implement AJAX and many user’s have already been explored from dynamically filling dropdown menus to image galleries that only load the images you are looking at or about to view. This is all based on the ECMA script language and the XMLHttpRequest object.
“First and foremost, AJAX is about improving user experience; user experience improvements fall into two categories: making current tasks easier and making previously impossible tasks possible.” (Eichorn, 2006). As developers aim to use AJAX to create an improved experience this should include those who have a disability. With the introduction of AJAX Yates’ argument of usability and accessibility work together is proven wrong. AJAX implemented correctly improves usability but the use of client side scripting and dynamically loaded content reduces the accessibility for some disabled users.
As AJAX relies heavily on client side scripting it is important to understand the difficulties this can produce.