PHP Hacks - Ajax Applications vs Traditional Web applications

Ajax is Different…

Ajax is a method of employing JavaScript, DHTML, and the XMLHttp behavior in the browser to provide truly dynamic content on a Web page without a page refresh. Popular examples of this technology include Google's Suggest, Amazon's Diamond Search tool, and many of Flickr.com's interactive features. Ajax effectively does away with the traditional "Click-and-Wait" Web-application architecture of yesterday, making it possible to provide the responsiveness and interactivity users expect from desktop applications. Ajax's ability to pull data from the server after the page has loaded contrasts with what we now refer to as the "traditional architecture".

In a traditional architecture, the user must wait for the entire Web page to reload to see new results from the server. In an application that requires a lot of interactivity with the business layer sitting on the server, the user must reload the entire page many times. This has implications for the efficiency of workflow, the load placed on the server hosting the application, and the productivity of users.

Where Do the Benefits of Ajax Come From?

Often, in business, decision makers are interested mainly in how information technology can reduce costs, or make better use of information assets. The benefits of Ajax seem to come more out of the cost-containment arena than the latter. The question becomes "Where do these cost savings come from and how can we quantify them?"

1.   Potentially Measurable Benefits

These are benefits that can be measured and expressed in terms of money. Regardless of the quality of your Ajax UI, you will look to these metrics to estimate value. They include:

•   Time spent waiting for data to be transmitted: Over many repetitions, the time employees spend waiting for the page to load can add up to significant costs.
•   Time spent completing a particular task: Increased efficiency in the user interface can often mean that time is saved at the task level, offering opportunities for concrete cost savings there.
•   Bandwidth consumed for the entire task: If repetitious tasks consume a lot of bandwidth, these costs can escalate dramatically. The amount of bandwidth consumed also has implications for time savings.

2.   Hard to Quantity Benefits

Some of the benefits associated with good user interfaces are qualitative and difficult to measure precisely. This isn't to imply they are not of financial value, but many business benefits are hard to quantify, and seasoned IT managers will know intuitively they can translate into significant bottom line savings. For Ajax, the opportunities for streamlining the interface are limited only by our imaginations, and it should also be noted that it's still possible to design a terrible UI with Ajax that doesn't benefit from any of the following:

o   Steps to complete a task: Reducing the number of steps has implications for the amount of time consumed but also for the number of opportunities for error.
o   Familiar user interface: Quite often these days, Web-based applications are used to replace desktop applications that had superior user interfaces. The benefits of offering users a similar or even just a familiar user interface to what they use on the desktop means lower training costs, fewer errors, and greater initial productivity.
o   Improved application responsiveness: More responsive applications can improve productivity not just by reducing "wait," but by promoting a more fluid, uninterrupted workflow. In a responsive application, users can move rapidly from one action to another as quickly as they can visualize the workflow. Less responsive applications can defeat the user's workflow visualization by forcing them to continually wait for program information.

Conclusion

There are clearly demonstrable, quantifiable advantages to using an Ajax architecture in a Web application. These cost savings originate primarily from time savings, but also from reductions in bandwidth requirements.