Eye gaze of is an informative social signal in interactions with other humans and also with virtual agents (VA). But for a successful communication, users have to accurately perceive the VA's point of gaze (POG). In our study, participants sitting opposite to a VA at a table indicated its POG by positioning a token on the table surface. We measured the perceptual accuracy within and between participants as well as the participants' response times and eye movements for five horizontally aligned gaze targets. We demonstrated that perceiving the VA met perceptual benchmarks from human lookers: a) variances within and between participants were only slightly larger, b) the VA's visual angle was linearly overestimated, and c) variances increased with the visual angle. Finally, participants showed large individual differences but were consistent in their own gaze behaviour and response times across trials and gaze targets.

Regarding the future usage of social robots in workplace scenarios, we addressed the question of potential mere robotic presence effects on human performance. Applying the experimental social facilitation paradigm in social robotics, we compared task performance of 106 participants on easy and complex cognitive and motoric tasks across three presence groups (alone vs. human present vs. robot present). Results revealed significant evidence for the predicted social facilitation effects for both human and robotic presence compared to an alone condition. Implications of these findings are discussed with regard to the consideration of the interaction of robotic presence and task difficulty in modeling robotic assistance systems.

We examined the effects of a robots' nonverbal response on evaluations of anthropomorphism and other dimensions (e.g., liking, closeness, pleasantness of human-robot interaction) in a case study. Our work both conceptually replicates and extends previous research: On the one hand, we replicated previous findings and generalized them to a different robot type, the iCat. On the other hand, our work extends existing research in that it includes a wider range of dependent variables, with a particular focus on perceptions of anthropomorphism. Taken together, most of our results support the experimental hypotheses for the dependent measures: That is, a robot that provided emotional feedback during the interaction was perceived to be superior to a robot that responded neutrally. Thus, our findings highlight the importance of the interplay of form and function in the attribution of humanness to robots.