First, we identified a set of business critical tasks that customers should be able to complete quickly with the web site. Then we carried out a usability expert review of the web site. This enabled us to identify and fix any "usability bloopers" that might slow users in an actual test.
Next, we carried out the usability testing. We asked 8 regular online shoppers to use the web site and noted the problems they experienced in completing the tasks. We made pixel-perfect recordings of the participant's screen for later analysis, recorded user actions like keystrokes and mouse clicks and simultaneously recorded synchronised video of the user.
Over 20 members of the development team visited our usability lab to observe the sessions, which gave us the opportunity to discuss the usability issues as they arose.
As well as identifying a number of usability "quick wins" that could be implemented immediately, the testing allowed the retailer to fix usability problems with advanced and untested functionality.