Interview du Guru de l'utilisabilité : Jakob Nielsen

Sur les performances

The main problem for response times today is not download delays, but rather server delays, as people stick too many widgets and dynamic objects on their pages.

Remember: 1.0 sec. response time, or users won’t feel that they’re navigating freely. Also remember that direct-manipulation options, such as within-page AJAX controls require 0.1 sec. response times to avoid feeling sluggish.

Sur les tests

For example, it’s wrong to test with your friends or colleagues. You need to bring in external users who are representative of the target audience and who don’t know anything about your project. And you can’t just let them fool around: they have to do real tasks. And, of course, you have to keep from biasing their behavior and giving them hints about how to use the site.

You don’t need any equipment, video cameras, one-way mirrors, or analysis software. You don’t even need a computer, if you’re testing a paper prototype.

Otherwise, a laptop or any other available computer will do, and you can run the test in a small conference room or even a regular office.

You do have to close the door, though, to avoid disrupting the user and to safeguard their anonymity, so you can’t test in a cubicle. Just tape a note to the door saying « Usability Test In Progress: Do Not Disturb ». (And remember to take it down between sessions, or people will stop respecting the sign.)

Sur l'utilisabilité

Usability is always relative to two things: who are the users, and what are they trying to accomplish with the UI?

That’s why we can’t just have one recommended design and just replace the logo to create a new site.

So, for example, if people are trying to just deal with a small number of things, you could simply list them all.

But if the task required users to consider a large number of options, you would need features to find, select, winnow, and sort the options, plus maybe even some kind of visualization tool.

Conclusion

Simplicity is usually the better choice.

Des années que j'essaye d'expliquer que rien de mieux que la simplicité pour être durable. Plus facile à dire qu'à faire. Lire l'intégralité de l'interview : Interview with Web Usability Guru,
Jakob Nielsen.