This paper examines human perceptions of humanoid robot behavior, specifically how perception is affected by variations in head tracking behavior under constant gestural behavior. Subjects were invited to the lab to "play with Nico," an upper-torso humanoid robot. The follow-up survey asked subjects to rate and write about the experience. A coding scheme originally created to gauge human intentionality was applied to written responses to measure the level of intentionality that subjects perceived in the robot. Subjects were presented with one of four variations of head movement: a motionless head, a smooth tracking head, a tracking head without smoothed movements, and an avoidance behavior, while a pre-scripted wave and beckon sequence was carried out in all cases. Surprisingly, subjects rated the interaction as most enjoyable and Nico as possessing more intentionality when avoidance and unsmooth tracking were used. These data suggest that naive users of robots may prefer caricatured and exaggerated behaviors to more natural ones. Also, correlations between ratings across modes suggest that simple features of robot behavior reliably evoke notable changes in many perception scales.
['Emily A. Wang', 'Constantine Lignos', 'Ashish Vatsal', 'Brian Scassellati']
Effects of head movement on perceptions of humanoid robot behavior