Much traditional user interface evaluation is conducted in usability laboratories, where a small number of selected users is directly observed by trained evaluators. However, as the network itself and the remote work setting have become intrinsic parts of usage patterns, evaluators often have limited access to representative users for usability evaluation in the laboratory and the users' work context is difficult or impossible to reproduce in a laboratory setting. These barriers to usability evaluation led to extending the concept of usability evaluation beyond the laboratory, typically using the network itself as a bridge to take interface evaluation to a broad range of users in their natural work settings.