Asynchronous JavaScript And XML, or its acronym Ajax, is a Web development technique for creating interactive web applications. In this post I describe the benefits to end users, introduce some examples of Ajax use on the web and have a look behind the scenes to explain how the magic works.

Benefits to end users

The key benefit of Ajax for end users is they are likey to experience an increase in the web page’s interactivity, speed, and usability. Put simply, Ajax achieves this by shifting a great deal of interaction to the end users computer, exchanging data with the server behind the scenes, so that the entire web page does not have to be reloaded each time the user makes a change.

This has great potential for community sites like the knowledge community, where changing information is often surrounded by feature panels and navigation elements.

Examples of Ajax use on the web

Jesse Garrett says,

Take a look at Google Suggest. Watch the way the suggested terms update as you type, almost instantly. Now look at Google Maps. Zoom in. Use your cursor to grab the map and scroll around a bit. Again, everything happens almost instantly, with no waiting for pages to reload… [These] are two examples of a new approach to web applications … [known as] Asynchronous JavaScript + XML, and it represents a fundamental shift in what’s possible on the Web.’

How the magic works

According to Wikipedia, Ajax is not a technology in itself, but a term that refers to the use of a group of technologies together. The Ajax technique uses a combination of:

• XHTML (or HTML) and CSS for marking up and styling information.
• The DOM accessed with a client-side scripting language, especially ECMAScript implementations like JavaScript and JScript, to dynamically display and interact with the information presented
• The XMLHttpRequest object to exchange data asynchronously with the web server. In some Ajax frameworks and in some situations, an IFrame object is used instead of the XMLHttpRequest object to exchange data with the web server.
• XML is commonly used as the format for transfering data, although any format will work, including preformatted HTML, plain text, JSON and even EBML.

Connecting magic models

On a theoretical level there’s a lot in common with this approach to web development and organisational development using the Lean thinking methodology. Lean thinking is a method to help an organisation, group or project team to improve the productivity, efficiency and quality of its products or services. The founding principle is that no work should be done unless it is going to create a better experience for customers. By clearly defining value for a specific product or service from the end customer’s perspective, all the non value activities, or waste, can be identified and removed step by step. The Ajax technique allows the non value activities to occur ‘behind the scenes’ creating space for all the value activities in the ’shop window’.