I was chatting to Keith about the XP vs Interaction Design article below. The interesting part is that the combination of Interaction Design and XP was exactly what we used for phase two of the project we're just finishing up now. One or two people from outside the programming team went away, worked with the customer, produced prototypes of the desired functionality, and then delivered them to the programmers to make work. That seems a lot like the combination that Alan Cooper was proposing.

In the end it worked quite well. It wasn't perfect - the prototypes left a lot of questions unanswered as far as the particulars of the application went, and those particulars often were the difference between a little code and a great deal of code, but it was certainly better than the requirements vacuum we were living in for phase one.