A documentation research project to study the complex issues facing the historical documentation of multi-institutional collaborations in physics and allied sciences. Phase III focused on four disciplinary areas of ground-based astronomy, materials science, heavy-ion physics, and medical physics, and a category named computer-mediated collaborations. The Astrophysical Research Consortium (ARC) study was part of a series of four cases to study collaborations that built astronomical observatories. Their design and construction were subject to collaboration management. The ARC built the observatory at Apache Point, New Mexico. The collaboration included the University of Chicago, University of Washington, Washington State University, Princeton University, and New Mexico State University. The objective was to build an optical telescope approaching national-observatory capabilities at 1/4 to 1/3 the cost. Subsequently, the collaboration added Johns Hopkins University and the Institute for Advanced Study to develop a digital sky survey project that did not include New Mexico State or Washington State. Universities contributed their own funds to cover most of the costs of the telescope, but the National Science Foundation funded site development and contributed a mirror whose design and construction it was independently supporting. The Sloan Foundation paid half the costs of the sky survey, whose formal title is the Sloan Digital Sky Survey (SDSS). The optical telescope was in operation and SDSS was in construction at time of interviewing.