An interactive system for interacting with a sentient being. The system includes a robotic companion of which the sentient being may be a user and an entity which employs the robot as a participant in an activity involving the user. The robotic companion responds to inputs from an environment that includes the user during the activity. The robotic companion is capable of social and affective behavior either under control of the entity or in response to the environment. The entity may provide an interface by which an operator may control the robotic companion. Example applications for the interactive system include as a system for communicating with patients that have difficulties communicating verbally, a system for teaching remotely-located students or students with communication difficulties, a system for facilitating social interaction between a remotely-located relative and a child, and systems in which the user and the robot interact with an entity such as a smart book. Also disclosed are control interfaces for the robotic companion, techniques for rendering the robotic companion sensitive to touch and responding to those touches, and techniques for providing quiet, back-drivable motion to components of the robotic companion.