Computer-supported cooperative work (CSCW) is an interdisciplinary research area concerned with developing computing technologies that facilitate, mediate, or regulate interaction between people engaged in cooperative work or similar kinds of sustained social activities. CSCW is a heterogeneous enterprise, addressing a motley of computational technologies and assimilating contributions from a host of scientific disciplines. What unites CSCW research is a shared concern with the fundamental problem of incorporating models of coordinative practices in computational artifacts and to do so in such a way that actors are able to deal with contingencies and are supported in that by the functionalities of the computational artifacts. Reflecting this shared concern, CSCW research is also united in a symmetrical commitment to ground design efforts in studies of actual work practices and to orient studies of actual work practices towards informing the development of collaborative technologies. As a field, CSCW focuses on a variety of domains where complex cooperative practices occur. Due to the heterogeneity of the field and of such domains, a range of approaches and frameworks are applied to CSCW research. A notably established approach that has shaped a substantial part of CSCW scholarship and had influence beyond the discipline is in-depth ethnographic studies of actual practices in their naturally occurring settings. In this regard, CSCW has been influential in championing a hybrid approach to the study of computing systems encompassing concerns for understanding and for designing.