is a usability evaluation method, usually used in expert reviews
, that enables experts to uncover usability problems without involving real users. For this method to be successful, it is important to clarify beforehand who the users are and what tasks they are carrying out with the product. Based on this knowledge, experts put themselves in the users' position and complete their typical tasks. Every time the expert has troubles or is even unable to complete a task, the expert identifies the cause and, thereby, uncovers existing usability problems.