The Influence of a Robot's Embodiment on Trust: A longitudenal Study

Abstract

Trust, taken from the human perspective, is an essential factor that determines the use of robots as companions or care robots, especially given the long-term character of the interaction. This study investigated the influence of a robot's embodiment on people's trust over a prolonged period of time, where embodiment entailed the distinction between a physical robot and a virtual agent. The participants engaged in a collaborative task in 10 sessions spread over a period of 6 weeks, with either a physical robot or a virtual agent. While our results showed that the level of trust was not influenced by the type of embodiment, and no interaction between time and embodiment was found, time alone was an important factor showing a significant increase in user's trust. Behavior analysis showed that participants at first felt significantly more uncomfortable interacting with a physical robot with respect to a virtual agent. This trend changed over time, as eventually participants interacting with the physical robot felt more comfortable than participants who interacted with the virtual agent. We emphasize the importance of long-term HRI studies and the use of objective measurements in these studies. The results found in this research project raise new questions on the role of the embodiment in trust and contribute to the growing research in the area of trust in human-robot interaction.