Assessing Perceived Discomfort and Proxemic Behavior towards Robots: A Comparative Study between Real and Augmented Reality Presentations

This paper assesses the usefulness of immersive technology to evaluate perceived discomfort and proxemic behavior towards a robot depending on its size. Therefore, we compared a real and an augmented reality (AR) robot presentation. In a within-subject design, a service humanoid approached participants (N = 32) in four trials in a counterbalanced order. One trial presented a real robot, another showed a same-sized AR version, and two trials showed down-scaled AR versions of the robot. The perceived discomfort and the comfort distance were measured. For the presentation mode comparison, the distance estimation error was measured additionally. The results show that the comfort distance was greater for the AR robot than for the real one. The comfort distance was also greater for the largest robot compared to the smaller sizes, while there was no difference when comparing the smaller ones. There was no difference in perceived discomfort between the presentation modes or the robot sizes. The distance estimation error was greater in AR. The study indicates that results obtained with the AR and real robot are comparable relative to each other. Therefore, utilizing AR could effectively evaluate various versions of robots in terms of the discomfort they induce—a critical prerequisite prior to the manufacturing process. Finally, AR might provide better validity for the evaluation of subjective measures.