Rethinking Web Apps
Google have done some groovy things recently, and done a lot to bring ‘Ajax’ to public attention. The ease of use of the zoomable draggable map is very nice, but this sort of sea-change in usability is really going to pay off in a different area, in my humble opinion.
Alan Cooper has written some useful words about usage patterns, and defines two key usage modes; transient and sovereign. A transient application might be used every day, but only in short bursts, and usually as a secondary activity. A sovereign application, in contrast, must cope with the user’s full attention for several hours at a time.
Many applications are inherently transient or sovereign. A writer’s word processor is a sovereign application, for example, around which a number of transient functions will revolve, such as the file manager (often embedded into the word processor as a file save or open dialog), a dictionary or spell-checker (again, often embedded), and an e-mail or messenger program for communicating with colleagues. To a software developer, the text editor or IDE is sovereign, as is the debugger.
Sovereign applications are also often used more intensely. Remember, a well-behaved user interface should be invisible. A good yardstick for the intensity of work is the effect of on the user’s workflow of the UI stalling, and reminding the user that it exists. If I’m simply moving files from one folder to another and hit a 2-second delay, I can cope quite happily. The same 2-second delay encountered while composing a visual masterpiece in a paint program, or in the middle of a heavy debugging session with some tricky code, I might get a bit upset with it.
Few people will be able to sustain a map-browsing session for several hours at a time, however cool it is. For the majority of users, such an activity will be low-stress, and leisurely. In other words, Google Maps is a transient application. So are most of the very large public web-based applications out there. Since the dawn of the internet, pundits have been predicting the demise of the traditional desktop office suite under the onslaught of web-based solutions. Ten years later, it hasn’t happened. Classic Web-page based solutions are good enough for transient use, but not for sovereign use.
Is Ajax going to change that? In my day job, I’m delivering ajax-based solutions to corporate users who will use them as their sovereign application (although we didn’t know it was Ajax back when we started). And the finance industry is known for being conservative. Let’s stay tuned.