This or That: The Effect of Robot's Deictic Expression on User's Perception

Abstract

The purpose of this study is to investigate a robot's impression perceived by users as well as the accuracy of perception of location information, which the robot provided according to the modality type of the robot. To explore this, we designed two 2 (verbal types: deictic vs. descriptive) x 2 (nose pointing: with nose vs. without nose) x 2 (eye pointing: with eyes vs. without eyes) mixed-participant studies. In the first study, we investigated the impacts of the robot's modality type in the imperative pointing situation. As a result, participants identified the robot's pointing gesture with nose as more effective, social, and positive, than the robot's pointing gesture without nose. Moreover, the descriptive speech robot was evaluated as more positive than the deictic speech robot. In terms of the accuracy of perception of location information, which the robot provided, participants identified the robot-designated chair more accurately when the robot delivered a deictic speech than when the robot delivered a descriptive speech. For the second study, we explored the effects of the robot's modality type in the declarative pointing situation. As a result, the robot's descriptive speech was rated as effective, social, natural, competent, trustworthy, and more positive than deictic speech. In the case of the robot's pointing gestures, pointing gesture with nose was evaluated as more effective, social, natural, competent, trustworthy, and positive than that without nose. In terms of the accuracy of location information perception, participants perceived the location of the object designated by the robot more accurately when the robot used descriptive speech, pointed with nose and without eyes.