Social sensing: when users become monitors

Adaptation requires a system to monitor its operational context to ensure that when changes occur, a suitable adaptation action is planned and taken at runtime. The ultimate goal of adaptation is that users get their dynamic requirements met efficiently and correctly. Context changes and users' judgment of the role of the system in meeting their requirements are drivers for adaptation. In many cases, these drivers are hard to identify by designers at design time and hard to monitor by the use of exclusively technological means by the system at runtime. In this paper, we propose Social Sensing as the activity performed by users who act as monitors and provide information needed for adaptation at runtime. Such information helps the system cope with technology limitations and designers' uncertainty. We discuss the motivation and foundations of Social Sensing and outline a set of research challenges to address in future work.