A major advantage of virtual organizations (VOs) is flexible membership and participation. In many VOs, members are able to join and leave at will, and can change whom they collaborate with at any point in time. This flexibility can be a source of increased effectiveness as VO structures are more readily able to adapt to contingencies and VO leadership can evolve over the course of a VO's lifecycle. This project examines the relationship between structural fluidity, VO leadership, and VO performance. The investigators will examine the log data generated by the technical systems used for coordination and information sharing in four different types of VOs (software engineering, disaster relief, online learning, and public discourse communities), will interview VO participants, and will measure VO performance in context-specific ways. The project will: (1) develop tools to measure organizational fluidity and make that fluidity visible to VO participants; (2) examine the relationship between organizational performance, the fluidity of group membership and fluidity of leadership in virtual organizations. The techniques pioneered in this proposal will increase understanding of how to use technical system log data to more quickly identify the most effective social structures and leadership strategies in VOs. The results and tools developed in the course of the project will have practical value for those seeking to improve VO performance for science, industry and government organizations that increasingly rely on virtual organizations for their success. A number of undergraduate and graduate students will participate in the project, furthering their training and education in interdisciplinary research.