The relation between children's shyness and their contingent dialogical actions when reacting to a social robot's instructions.

Dialogical actions are contingent in humans and also need to be contingent when implemented on intelligent systems such as social robots in order to ease human-robot interaction. Whereas current studies suggest that social robots can support children in different contexts, little is known about individual differences in the way children react to their instructions within an interaction. One dimension of individual differences is temperamental shyness-a tendency to be reluctant in novel social situations. The literature suggests that shyness might influence contingency patterns, and effective robots would need to adapt to this. This study aims to analyse the patterns of dialogical actions in preschoolers (N = 28) in a long-term interaction as a function of their shyness level. In two consecutive sessions in which a robot taught the children novel words, we investigated latencies between the robot's prompt and the child's corresponding action. Results showed that higher levels of shyness were associated with increased action latencies, particularly in the first session. However, this effect diminished over time, because latencies decreased from the first to the second session. The discussion focuses on the findings on the role of shyness in interactions with increasing familiarity, and their implications for a robot's partner modelling. This article is part of the theme issue 'Mechanisms of learning from social interaction'.