Supporting mobile collaborative work over wide areas is challenging due to the limitations and unreliability of wide area wireless networks. However, variations in patterns of collaboration require different levels of timeliness and synchrony, and place different demands on groupware and its supporting technologies. In this paper, we argue that groupware supported by wide area mobile networks strongly favors loosely coupled work, where workers are autonomous and require a reduced level of communication. We examine the relationship between loosely coupled group characteristics and wide area mobile groupware by considering one particular loosely coupled group-teams of home care workers. Over a two-year period, we analyzed home care work practices, and designed and field tested Mohoc, a mobile groupware application to support home care work. From this experience, we identified four characteristics of loosely coupled groups that enable workers to accommodate the uncertainty of wide area mobile groupware: autonomy and the partitioning of work, clear ownership of data and artifacts, asynchronous awareness, and explicit asynchronous communication.