Empowering end users to customize their smart environments: Model, composition paradigms, and domain-specific tools

Research on the Internet of Things (IoT) has devoted many efforts to technological aspects. Little social and practical benefits have emerged so far. IoT devices, so-called smart objects, are becoming even more pervasive and social, leading to the need to provide non-technical users with innovative interaction strategies for controlling their behavior. In other words, the opportunities offered by IoT can be amplified if new approaches are conceived to enable non-technical users to be directly involved in "composing" their smart objects by synchronizing their behavior. To fulfill this goal, this article introduces a model that includes new operators for defining rules combining multiple events and conditions exposed by smart objects, and for defining temporal and spatial constraints on rule activation. The article also presents the results of an elicitation study that was conducted to identify possible visual paradigms for expressing composition rules. Prototypes implementing the resulting visual paradigms were compared during a controlled experiment and the one that resulted most relevant for our goals was used in a study that involved home-automation experts. Finally, the article discusses some design implications that came out from the performed studies and presents the architecture of a platform supporting rule definition and execution.