Path Analysis for the Halo Effect of Touch Sensations of Robots on Their Personality Impressions

Physical human–robot interaction plays an important role in social robotics, and touch is one of the key factors that influences human’s impression of robots. However, very few studies have explored different conditions, and therefore, few systematic results have been obtained. As the first step toward addressing this issue, we studied the types of impressions of robot personality that humans may experience when they touch a soft part of a robot. In the study, the left forearm of a child-like android robot “Affetto” was exposed; this forearm was made of silicone rubber and can be replaced with one of other three forearms providing different sensations of hardness upon touching. Participants were asked to touch the robot’s forearm and to fill evaluation questionnaires on 19 touch sensations and 46 personality impressions under each of four conditions with different forearms. Four impression factors for touch sensations and three for personality impressions were extracted from the evaluation scores by the factor analysis method. The causal relationships between these factors were analyzed by the path analysis method. Several significant causal relationships were found, for example, between preferable touch sensations and likable personality impressions. The results will help design robots’ personality impression by designing touch sensations more systematically.