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Prescribing AJAX: Panacea, Placebo, or Poison? Peeling the AJAX Onion

Mike Padilla will be speaking at AJAXWorld Conference & Expo 2008 East, March 18-20, 2008, in New York City
By Mike Padilla
Article Rating:
December 5, 2007 10:30 AM EST
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 7,190
Websites that have a high number of interactions, relevant to a common node, each that result in small content changes such that the overall context of the page does not change significantly, are  most likely to benefit from AJAX. Gmail is a good example. On the flipside, websites that have few interactions relevant to a common node, each that result in the majority, if not all, of the content to change, are least likely to benefit from AJAX. Wikipedia.com is a good example.
 
When most of the page content changes, AJAX is probably ill-suited. If a large portion of the page is changing, there is less context to maintain. The amount of information that is being transferred is proportionately high so any benefit from retrieving data and populating it into the existing webpage rather than having to retrieve an entirely new webpage is limited. There is overhead associated with the client-side parsing of the data returned via AJAX that is proportional to the amount of data. Users are also more likely to expect the back button to work when the majority of a page’s content changes as compared to when just a small snippet of content is updated.
 
Another characteristic related to AJAX suitability is the user/website communication ratio. How much information is the user providing versus how much information is the website providing? If you are dealing with a traditional, brochureware website that users access to only retrieve content, the communication is primarily one-way from the website to the user. Such websites are less likely to benefit significantly from a full blown AJAX implementation.
 
If you have a transactional web application, such as an internal operations web application to handle insurance claims, the communication is more balanced between the user and the application. The user inputs large amounts of data to which the application must respond accordingly. This two-way communication is usually much more fluid and efficient if it takes place across small fragments rather than entire page loads. AJAX can smooth out such communications.
 
Accordingly, if you find yourself enhancing an informational website with rich functionality, you should do so judiciously, primarily complementing existing functionality. If you’re charged with converting a legacy application to a web application, you will more likely incorporate rich functionality across the board to support the interactions required for such a transactional system.
 
The applicability of AJAX can also vary between internal web applications and external, public websites. Search engine visibility is an important consideration for public websites while completely not needed for an internal web application. The potential lack of search engine visibility that can accompany AJAX is therefore a major drawback for a public website while insignificant for an internal web application.
 
AJAX’s impact on accessibility issues can also vary between the two. The Americans with Disabilities Act (ADA) "prohibits discrimination on the basis of disability in employment, programs and services provided by state and local governments, goods and services provided by private companies, and in commercial facilities." Websites and web applications are included as covered entities. For example, an employer may be required to provide equal access to an AJAX app that is not screen reader friendly to a visually impaired employee. If the application did not use AJAX, it likely would have been screen reader friendly and no further accommodations would be necessary.

Published December 5, 2007 – Reads 7,190
Copyright © 2007 SYS-CON Media, Inc. — All Rights Reserved.
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More Stories By Mike Padilla

Mike Padilla is a user experience manager at Vanguard. He has led front-end development efforts for such companies as Fleet Credit Cards, Mellon Private Asset Management, The Bank of New York, Radian Guaranty, and Bessemer Trust. Macromedia has featured his usability designs. He received a B.S. in mechanical engineering, focusing on ergonomics, from Cornell University.
Padilla is an ardent advocate of high-fidelity prototyping during requirements development. In his spare time, he designed and developed Protonotes, a free AJAX web service that allows project team members to discuss system functionality, design, and requirements directly on prototypes with "sticky notes".

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AJAXWorld News Desk 12/05/07 10:46:23 AM EST

Ever since Jesse James Garrett coined the term AJAX to describe the collection of existing technologies that allow increased responsiveness and interactivity of webpages, its adoption has been embraced across the Web. But have designers and developers gone overboard? Is everything a nail to be pounded with the AJAX hammer? Some of the fundamental technologies that AJAX is based on, including HTML, CSS, and JavaScript, can sometimes offer simpler, more elegant solutions that are better suited to certain user experiences.