The moderator of ausability testwalks the participant through the test. The moderator welcomes theparticipant, and explains procedure and intention of the test. Then, themoderator guides the participant through test tasks, responds topossible questions, and asks questions in order to investigate oncauses for usability problems. At the same time, the moderatorobserves exactly how the participant solves the tasks, and capturesoccurring usability problems.
Moderating a usability test is a demanding task. The moderator isresponsible for a number of things: s/he makes sure the participantfeels comfortable, acts as a time keeper in order not to exceeddefined time frames, asks questions, and makes sure that theparticipant is not distracted or influenced by anything. Especiallythis last aspect requires practice and experience, as every actionmight influence the participant and therefore affect test results.