Group-Robot Interaction in the Wild: An Exploratory Field Study in Semi-public Spaces

How does interaction with robots differ between spontaneously formed groups and individuals? Despite increasing robot deployment in public spaces, this question remains understudied in real-world settings. We conducted a field study deploying a service stationary robot in semi-public office spaces, tracking 221 individuals (42 alone, 179 in groups) across 95 interaction opportunities. Cookies were placed on accessible trays, creating a low-barrier functional interaction opportunity (taking a cookie) while allowing observation of spontaneous social behaviors. Groups demonstrated significantly higher engagement: functional interactions and social gestures. Within groups, leader presence amplified social engagement threefold. These findings are consistent with descriptive norm theory: group presence and leader behavior were associated with increased social engagement, though context-specific factors may moderate these effects. Results highlight the potential value of group detection for robots in multi-user environments, and demonstrate the feasibility of integrating psychological theory with automated tracking to study spontaneous human-robot encounters in the wild.