From When to When: Evaluating Naturalness of Reaction Time via Viewing Turn around Behaviors

Abstract

This paper addresses the effects of visual reaction times of a turn around behavior toward touch stimulus in the context of perceived naturalness. People essentially prefer a quick and natural reaction time to interaction partners, but appropriate reaction times will change due to the kinds of partners, e.g., humans, computers, and robots. In this study, we investigate two visual reaction times in touch interaction: the time length from the touched timing to the start of a reaction behavior, and the time length of the reaction behavior. We also investigated appropriate reaction times for different beings: three robots (Sota, Nao and Pepper) and humans (male and female). We conducted a web-survey based experiment to investigate natural reaction times for robots and humans, and the results concluded that the best combinations of both reaction times are different between each robot (i.e., among Sota, Nao and Pepper) and the humans (i.e., between male and female). We also compared the effect of using the best combinations for each robot and human to prove the importance of using each appropriate reaction timing for each being. The results suggest that an appropriate reaction time combination investigated from the male model is not ideal for robots, and the combination investigated from the female model is a better choice for robots. Our study also suggests that calibrating parameters for individual robots’ behavior design would enable better performances than using parameters of robot behaviors based on observing human-human interaction, although such an approach is a typical method of robot behavior design.