As im trying to gather usability requirements my focus is early in the development process. As I understand it, all of the above could be used for both new systems and when parts of a system needs to be removed/changed.
All are used to gather information about the users needs and "what they are doing". One of the differences between the above mentioned methods that I see is that the usability test will tell you which parts of the system that's perceived as being "positive".
What's your view?
Thanks in advance,
p.s. litterature, links ect. are also appriciated.
Google on "Usability requirements" turned up a lot of interesting stuff. The first one I got was about "Six Styles..." which looked like a useful overview. A search for "usability testing" will probably be just as interesting. For academic info on the whole field, look for "HCI" or "Human Computer Interaction" or CHI for, well, you can guess. I recall finding a lot of good sites when I was bluffing my way through an HCI class.
I've only gotten customers to say vague things like "response time for most screens must be under ..." During UI design they often count keystrokes and clicks to compare alternatives. I think that's seriously wrong-headed but never had any luck talking them out of it. During testing we timed longer flows through several screens to accomplish a business goal. That made more sense. We wound up gaming the system - popping partially completed windows and doing asynchronous processing to make it feel more responsive when it really wasn't any faster. The numbers were worse, user satisfaction better.
A good question is never answered. It is not a bolt to be tightened into place but a seed to be planted and to bear more seed toward the hope of greening the landscape of the idea. John Ciardi