Usability Testing in Practice
http://wdvl.internet.com/Authoring/Design/UsabilityTesting/

Starling, Andrew
WDVL
2002

Abstract:

If you're interested in Web site usability then it's likely that you've come across the concept of professional usability testing. It's also likely that the practicalities of testing have remained a mystery, because very little has been published about it on the Web - until now.