This paper reports on a field trial with interactive humanoid robots at a science museum where visitors are encouraged to study and develop an interest in science. In the trial, each participating visitor wore an RFID tag while looking around the museum’s exhibits. Information obtained from the RFID tags was used to direct the robots' interaction with the visitors. The robots autonomously interacted with visitors via gestures and utterances resembling the free play of children [1]. In addition, they guided visitors around several exhibits and explained the exhibits based on sensor information. The robots were given high evaluations by visitors during the two-month trial. In addition, we conducted an experiment during the field trial to compare in detail effects of exhibit-guiding and free-play interaction under three operating conditions. The results revealed that the combination of free-play interaction and exhibit-guiding positively affected visitors’ experiences at the scie...