This paper explores how the adoption of mobile and social computing technologies has impacted upon the way in which we coordinate social group-activities. We present a diary study of 36 individuals that provides an overview of how group coordination is currently performed as well as the challenges people face. Our findings highlight that people primarily use open-channel communication tools (e.g., text messaging, phone calls, email) to coordinate because the alternatives are seen as either disrupting or curbing to the natural conversational processes. Yet the use of open-channel tools often results in conversational overload and a significant disparity of work between coordinating individuals. This in turn often leads to a sense of frustration and confusion about coordination details. We discuss how the findings argue for a significant shift in our thinking about the design of coordination support systems.

Despite the importance of individuals coming together for social group-activities (e.g. pick-up volleyball, chess clubs), the process by which such groups coalesce is poorly understood. Existing theories focus on adoption and contribution rates, group types, and the formation of group norms, as opposed to the processes involved in initial group coalescence. We address this gap in the literature through an interview study examining: 1) how well people's needs for social group activity engagement are being met; 2) the challenges they face in finding and participating in, and; 3) leading interest-based group activities. Our findings highlight how people-s needs are not being addressed by current technologies. In particular, they place a heavy burden on individuals to step forward into leadership positions where the return they will receive for their efforts is often unknown, or extremely limited. We discuss the implications of our findings for the design of interest-based group coalescing technology.