We introduce a conceptual framework that articulates the mechanics of collaboration for shared-workspace groupware: the low level actions and interactions that must be carried out to complete a task in a shared manner. These include communication, coordination, planning, monitoring, assistance, and protection. The framework also includes three general measures of these mechanics: effectiveness, efficiency, and satisfaction. The underlying idea of the framework is that some usability problems in groupware systems are not inherently tied to the social context in which the system is used, but rather are a result of poor support for the basic activities of collaborative work in shared spaces. We believe that existing low-cost evaluation methods— heuristic evaluation, walkthroughs, user observations and questionnaires— can be modified to include this framework in a way that helps a groupware evaluator uncover these usability problems.