This paper presents the propensities of preference for Human Robot Interaction (HRI) according to different personalities and facial expressions of humans and robots. This study is based on two types of personalities: extroverted and introverted. According to the personality, the facial expressions are distinguished to express extroversion and introversion. The design of experiment is a 3 (participant's group of personality: extrovert, intermediate, introvert) x 2 (robot's groups of personality) between-subjects experiment (N=40) in which participants interact with KMC-EXPR robots expressing either extroversion or introversion. The results showed an unprecedented hypothesis, unexpected implications and certain propensities of preferences.

This study explores the effect of the robot's appearance vs. behavior (voice and gestures) on the way it is perceived as a machine-like instead of a human-like robot. A between-subjects experiment with four conditions was conducted. Results suggest that both the robot's behavior and appearance are important but, if they are contradictory, the robot's behavior is more powerful than the robot's appearance in the perception of the robot as more machine-like or human-like.