Synthetic emotions and Gamification: Exploring Engagement Strategies for Small Social Robots in different age-groups

This paper investigates engagement strategies for pocket-sized social robots designed to aid children in the longer term with anxiety disorders. We explore engagement strategies for a pocket-sized tactile robot designed to support children with anxiety through daily interaction. The robot delivers either synthetic emotional feedback or gamified point rewards to encourage user participation. We evaluated these strategies through two studies conducted in contrasting age groups and settings: a school-based preference study with young children, and a full-day behavioral study with university students in naturalistic environments. The study with school children (aged 6-8, n=16) indicated a preference for emotional engagement over points-based approaches. The follow up study with university students (n=14) across a full day of interactions revealed contrasting results: points-based systems produced significantly higher task accuracy (p < 0.05) and sustained performance over time. Points-based participants also rated their robot as more human-like and likable, challenging assumptions about emotional expressiveness being necessary for positive robot perception. These findings across different age groups suggest that stated preferences may not predict behavioral effectiveness, with structured reward mechanisms demonstrating superior performance outcomes despite lower user preference ratings in younger populations. This work contributes insights into age-related differences in engagement strategy effectiveness in human-robot interaction design, highlighting the importance of behavioral validation alongside preference assessment in therapeutic robotics.