A bellboy robot: Study of the effects of robot behaviour on user engagement and comfort

• A Bellboy, social robot interacting guests in a hotel is presented.
• Social robot design should take care of target user age that influences use distance.
• A robotic body encourages remarkably HCI (with respect to common computers).
• A two-step salutation can attract user attention while avoiding intimidation.
• Multimodal systems are highly recommended in real, noisy environment.

This paper provides the results of various trial experiments in a hotel environment carried out using Sacarino, an interactive bellboy robot. We analysed which aspects of the robot design and behaviour are relevant in terms of user engagement and comfort when interacting with our social robot. The experiments carried out focused on the influence over the proxemics, duration and effectiveness of the interaction, taking into account three dichotomous factors related with the robot design and behaviour: robot embodiment (with/without robotic body), status of the robot (awake/asleep) and who starts communication (robot/user). Results show that users tend to maintain a personal distance when interacting with an embodied robot and that embodiment engages users in maintaining longer interactions. On the other hand, including a greeting model in a robot is useful in terms of engaging users to maintain longer interactions, and that an active-looking robot is more attractive to the participants, producing longer interactions than in the case of a passive-looking robot.