a b s t r a c tAdvancements in technology are bringing robotics into interpersonal communication contexts, including the college classroom. This study was one of the first to examine college students' communicationrelated perceptions of robots being used in an instructional capacity. Student participants rated both a human instructor using a telepresence robot and an autonomous social robot delivering the same lesson as credible. However, students gave higher credibility ratings to the teacher as robot, which led to differences between the two instructional agents in their learning outcomes. Students reported more affective learning from the teacher as robot than the robot as teacher, despite controlled instructional performances. Instructional agent type had both direct and indirect effects on behavioral learning. The direct effect suggests a potential machine heuristic in which students are more likely to follow behavioral suggestions offered by an autonomous social robot. The findings generally support the MAIN model and the Computers are Social Actors paradigm, but suggest that future work needs to be done in this area.