Getting Confidence from Lincoln
http://www.uie.com/articles/getting_confidence/

Spool, Jared M.
User Interface Engineering

Abstract:

A few years back, we conducted one of the most painful usability studies in the history of our research. We learned some really important things, but I'm not sure the users in that study will ever forgive us. Before that particular study, we'd noticed, when searching large web sites for information, there were some sites where users always seemed to know where to find the content. No matter what content they were seeking, every user somehow knew to make a bee-line for it. Not every site worked this way and we wanted to know what made these particular sites work so well.