Effect of back and mutual imitation on human´s perception of a humanoid´s imitative skill

A promising technology for teaching robots new skills is learning from demonstrations (LfD) or imitation learning. Even though there is currently large literature in imitation learning, smaller attention was given to studying social aspects of the imitation situation. Back imitation is the situation when the demonstrator (human) imitates the learner (robot) before engaging in the actual teaching. In this paper we study the effect of back-imitation on human´s perception of the robot´s imitative skill. This study is motivated by the need to improve the acceptance of the robot through increasing its perceived imitation skill. Our claim is that back-imitation can be used to achieve this goal. The paper provides two studies involving 24 subjects and 36 HRI sessions that were conducted to investigate this claim. Statistical analysis of the results of these studies show that participants assigned the robots with which they engaged in back-imitation higher scores in terms of imitative skill and overall performance compared with robots that they did not imitate. The paper discusses the implications of this result for the design of imitation situations and broader implications for HRI research.