mental models of persistence

mental models of persistence.
It is a challenge to introduce a new model of UI to the web. People are
clearly frustrated by the standard web application experience where
interaction has devolved into a series of forms. The RIA model provides
an opportunity to solve this problem.

Jonathan Boutelle writes about User Mental Models of Persistence in RIAs.
When we have the opportunity to keep some state on the client and let
people choose when to save or cancel, what should we do? Should we
return to the desktop application model of requiring an explicit save?

I agree that requiring a person to save their work can cause real
problems. While this is the standard approach in desktop applications,
perhaps its worth re-thinking.

In the user experience of a web application, changes are more
lightweight. At almost every click, you expect your changes to be
saved. This is usually the case in this environment where every click
implies a server round-trip. Perhaps this side effect of a bizarre user
interaction model actually introduces a nice model for persistence.

The web presents different kinds of tasks than a desktop
application. I'm not writing 100,000 lines of code when I use a web
application. You aren't writing a novel. We're answering questions,
filling in bits of data. There may be a lot of questions, the
transaction may have complicated dependencies, and we all may be
entering a googleplex of data, but this data is of a fundamentally
different form than the most of the documents we create on our

Web applications are by their nature transient. We are more likely
to use them for one minute than for an hour, and I would guess that we
use many more different web apps from different vendors than we use
desktop applications.

Perhaps a natural approach to a persistence model in this evironment
is to simply make it easy as easy to change data that has been
submitted as to submit it in the first place. This is possible in an
HTML web application and I frequently see well-designed web apps that
provide appropriate links and checkboxes to modify submitted data.
Using this model of persistence, it is essential to let people easily
see their “state” — where they are and what data they have entered so
far. It is in this area where many web apps fail and where RIAs offer
opportunities to improve the user experience. With a persistent UI on
the client, it is easier to provide appropriate cues to the person
using the application.. [Sarah Allen's Weblog]

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