We discuss the design ideal of explicit interaction, which is a way to approach the dimensions of explicitness versus ambience and explicitness versus obtrusiveness in ubiquitous computing. Explicit interaction refers to interaction techniques designed to make actions and intentions visible,understandable and accountable. We introduce three levels of analysis—usability, materialization, and social performance—and present the design of an explicit interaction assembly of devices for rehabilitation after hand surgery.The assembly, intended to support video recording during patient-therapist consultations, is evaluated and we find thatit provides superior usability and the potential to improve rehabilitation outcomes through materialization. Moreover,we find that the design of cues to support the social practice in the rehabilitation ward needs to be improved since the assemblyallowed for uses unanticipated during the design.