A Drink-Serving Mobile Social Robot Selects who to Interact with Using Gaze

Robots will soon deliver food and beverages in various environments. These robots will need to communicate their intention efficiently; for example, they should indicate who they are addressing. We conducted a real-world study of a water serving robot at a university cafeteria. The robot was operated in a Wizard-of-Oz manner. It approached and offered water to students having their lunch. Our analyses of the relationship between robot gaze direction and the likelihood that someone takes a drink show that if people do not already have a drink and the interaction is not dominated by an overly enthusiastic user, the robot's gaze behavior is effective in selecting an interaction partner even "in the wild".