Collaboratories are computer-supported systems that allow people to work with each other, facilities, and databases without regard to geographical location. Interdisciplinary research at the University of Michigan is exploring the impact of collaboratories in two domains. The Upper Atmospheric Research Collaboratory (UARC) is designed to increase access to distant facilities and scientists in the space physics community. The Medical Collaboratory is designed to increase contact between geographically distributed primary care physicians and radiologists in consultations over radiograph and ultrasound images. The development strategy in both projects is user-centered. Behavioral scientists contribute to this effort through characterization of conditions prior to collaboratory introduction and through measurement of changes produced by collaboratory use. A similar strategy is proposed for analysis of digital library efforts.Evaluation of electronic work: Research on collaboratories at the University of MichiganThe University of Michigan is a leader in the development of collaboratories. A collaboratory is the "...combination of technology, tools and infrastructure that allow scientists to work with remote facilities and each other as if they were colocated." (Lederberg & Uncapher, 1989, p. 6) A National Research Council (1993) report defines a collaboratory as a "...center without walls, in which the nation's researchers can perform their research without regard to geographical location--interacting with colleagues, accessing instrumentation, sharing data and computational resources [and] accessing information in digital libraries." (National Research Council, 1993, p. 7) A simplified form of these definitions describes a collaboratory as the use of computing and communication technology to achieve the enhanced access to colleagues and instruments provided by a shared physical location, but in a domain where potential collaborations are not constrained by temporal or geographic barriers.Currently there are two collaboratory efforts at the University of Michigan. The Upper Atmospheric Research Collaboratory (UARC), started in 1992, is an attempt to build a system to support science among an international community of space physicists focused on the Sondrestrom Upper Atmospheric Research Facility, located in Kangerlussuaq, Greenland (Clauer, 1994). The UARC interface provides data viewers that display real-time images of ionospheric phenomena, along with "chat windows" that allow scientists to discuss the displays by typing messages to one another. The UARC system became operational in April, 1993 and is now in use by physicists at eleven laboratories in North America and in Europe. When conceived, the principal motivations for the UARC system were concerns among space physicists that they were unable to respond rapidly to interesting ionospheric phenomena, that they did not have good opportunities to corroborate data from one instrument with data from other instruments, and that the end of the Cold War had eliminated low cost military flights to bases in Greenland near the Sondrestrom facility. In these terms, the UARC was envisioned as a system that would, as much as possible, re-create the experience of being in Greenland through use of the collaboratory technology.The Medical Collaboratory, started in 1995, is an attempt to build on lessons learned from UARC to support consultations between geographically distributed primary care physicians and radiologists over radiograph and ultrasound images. As in UARC, the Medical Collaboratory interface will provide viewers that display radiological images with annotations, but with the addition of video and audio conferencing. The Medical Collaboratory system is not yet operational, but is envisioned to connect doctors at satellite clinics in the vicinity of Ann Arbor with radiologists at the University of Michigan Medical Center.