By providing “thick client” functionality to websites, Ajax can make them behave drastically different than people might expect. After all, if people expect something to behave like a website and it behaves like Microsoft Word, you might have problems.

Also, Ajax is completely dependent upon JavaScript. If the user doesn’t have JavaScript enabled, or is using a browser that quirks up with your particular JavaScript, then they may be prevented from using your website. This would actually decrease usability.

Ajax can break standard Web conventions. It typically breaks the browser’s Back button. This can be worked around, but in its immature stages this problem is still very common in Ajax websites.

It’s also worth keeping in mind that a large portion of your users may have some sort of impairment. This could be particularly common in archives, where the average age of your users could be 50-60. Take a blind user, for example. Blind users use speech readers to surf the Internet, and if most of your content is dynamically loaded via Ajax, this content may unaccessible to these users. Features such as drag-and-drop will be completely unusable to them.

Ajax is a promising methodology, but sticking to good old Web standards like XHTML and CSS is often preferable.

I hadn’t checked out the Pepys diary website for a couple of years. They have since managed to build a Web 2.0-style community around this archival resource using RSS webfeeds, annotations (blog comments) and related discussion forums.

I’ve added it to my list of examples above. Thanks for pointing it out. Very interesting.

Thanks also for posting the Library 2.0 summary on your own blog. This article provides more insight into the noteworthy aspects of Web 2.0 and, in this case, how that applies to Library services.

I therefore see the introduction of community-managed collections, descriptions, exhibits and discussions as something that happens in parallel to the authoritative archives access systems that are managed by archival institutions and their professional staff. I see these parallel systems as taking the form of virtual collections or virtual research rooms that are loosely-coupled to the institutional systems using open architectures and standards.

I have often thought that the online Pepys diary represents a picture of the type of colaboration that would be beneficial to archivists. How many enlightening annotations could other archivists and patrons provide to our digital collections and finding aids, if we would only give them a format for doing so.

Thanks for writing on this topic!