Is there Really an Effect of Time Delays on Perceived Fluency and Social attributes between Humans and Social Robots? A Pilot Study

Humans are expert percievers of behavioural properties, including the timing of movements. Even short hesitancies and delays can be salient depending on the context. This article presents results from a pilot study on time delays in a human-robot interaction setting using the Wizard of Oz paradigm. Participants (n=17) played Tic-Tac-Toe with the humanoid robot Epi. They were randomized into one of three groups, where Epi either executed its movements with no delay, a short delay (4s) or a long delay (10s). Results from questionnaires measuring fluency, trust, anthropomorphism, animacy and likability were compared before and after the interaction and between the different groups. Although there was evidence of decreased perceived fluency after delays, the difference between the groups did not meet the threshold for statistical significance. The latter is true for our other measures used. We conclude that better statistical power is needed to be sure whether there is indeed an effect of time delays on robot-related attribution of social features. Suggestions are made in regards to how the study design could become more robust for a future, more large-scale study. In addition, we propose using measures that better account for the participants' embodied experiences by taking emotional and bodily states into consideration for future studies.