Since social robots are increasingly entering areas of people’s personal lives, it is crucial to examine what affects people’s perceptions and evaluations of these robots. In this study, three potential influences are examined: 1) the robot’s level of interaction skills, 2) the robot’s expected future role as a helpful assistant or a threatening competitor, and 3) people’s individual background with regard to robots and technology in general. In an experimental lab study with a 2x2 between-subjects-design (N = 162), people read a vignette describing the social robot Nao either as assistant or competitor and subsequently interacted with Nao, which either displayed high or low interaction skills. Results of a structural equation model show that the robot’s interaction skill level had the strongest effect, with a low level leading to a negative evaluation of the robot’s sociability and competence and subsequently a negative general evaluation of the interaction with the robot. A robot which was expected to become a competitor was also evaluated as less sociable than a robot expected to become an assistant. Overall, in case of an actual interaction with a social robot, the robot’s behavior is more decisive for people’s evaluations of it than their expectations or individual backgrounds.