Usability evaluations versus usability testing: when and why?

Usability evaluation and usability testing are defined and distinguished, and the role of expert evaluation in defining audience groups, constructing usage scenarios, and performing task breakdowns is pointed out. Usability evaluation is viewed as comparable to the work of an expert editor, and the background that a usability specialist should have is described. Other methods besides testing that can supplement expert evaluation are briefly discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>