This is a study of the social organization and dynamics of multi-institutional collaborations in the physical sciences. Included among such collaborations are studies in high-energy physics, ground-based astronomy, materials science, medical physics, and computer-centered collaborations. For nearly ten years the Center for History of Physics at the American Institute of Physics has collected interviews and archival materials for such collaborations. In the present project an interdisciplinary team will use the 580 interviews and thousands of pages of documents that describe these 56 large-scale collaborations to produce a quantitative and qualitative analysis of the characteristics, dynamics and performance of multi-institutional collaborations. Cluster analysis will be used to develop a typology of the forms of collaboration by their most important organizational and technological dimensions, and qualitative comparative analysis will be used to examine their relationships with important outcomes such as success, trust and conflict. Results will be reported in a book intended for scholars, policy makers and archivists.