Trust in socially assistive robots: Considerations for use in rehabilitation

•Social robots are a new entity in the realm of rehabilitation.•Trust is an important factor to consider when the goal is a long-term interaction with the robot.•Trust has been extensively studied in other robotic contexts, but not in the context of social robots in rehabilitation.•Social robots in rehabilitation is a unique context in terms of population and length of interaction.•Need to create empirical measures of trust that are accessible for people with disabilities. Incorporation of social robots into rehabilitation calls for understanding what factors affect user motivation and success of the interaction. Trust between the user and the robot has been identified as important in human-robot interaction and in human-human interactions in therapy. Trust has been studied in the context of automation technology, (e.g., autonomous cars), but not in the context of social robots for rehabilitation. In this narrative review, we address the unique patient-clinician-robot triad, and argue that this context calls for specific design features in order to foster trust with the users. We review pertinent methods for measuring trust, and studies demonstrating that culture, prior experience and propensity-to-trust affect to what extent users trust robots. We suggest design guidelines for fostering trust and methods for measuring trust in human-robot interactions in rehabilitation. We stress the need to create measures of trust that are accessible to people who suffer from speech or cognitive impairments. This review is pertinent to researchers, roboticists, and clinicians interested in designing and using social robots for rehabilitation.