A comparison of children’s behavior toward Sony’s robotic dog AIBO™ (ERS-210) and a similar sized live dog was made over time. Fourteen children between three and six years of age from a kindergarten and a pre-school play group in Zurich, Switzerland, were visited once a week for eleven weeks with the live dog and subsequently for eleven weeks with AIBO. We investigated the children’s spatial proximity toward AIBO and the live dog, and the rate of stroking and touching, the overall rate of interactions, and the rate of laughing in the presence of AIBO and the live dog. The children refused to participate in 18.2% of the sessions with the live dog and in 30.5% of the sessions with AIBO. Children who participated initiated approaches to AIBO significantly more often than to the live dog over the observation period. In contrast, there was no significant difference between the live dog and AIBO initiating the very first contact, even though the live dog approached the childr
en 24 times in 126 sessions, while AIBO approached the children only ten times in 107 sessions. The children tended to interact more with AIBO than with the dog. For example, AIBO was touched more often than the dog and there was also less laughter with the dog than with AIBO, but these differences were not significant. In contrast, the dog was stroked significantly more often than AIBO. AIBO started to play ball 44 times whereas the dog only started to play once. That the dog did not often play with a ball, whereas AIBO did, may have played an important role because the children liked this characteristic. That children touched and interacted more with AIBO could be because dogs are widespread in their society and therefore sometimes taken for granted. Nevertheless, 10 out of 14 children said they preferred the dog, three said both, and only one preferred AIBO. Because of the small sample size, strong conclusions can not be drawn from this study, but it may open the door for further research on human–pet and human–robot social interactions.