This analytic review is concerned with the interpersonal processes, and the characteristics of situations and persons that influence them, that lead to the confirmation and disconfirmation of expectations in the course of social interaction. We examine the steps in the chain of events by which the expectations of one person guide and direct the dynamics of social interaction such that the behavior of the target of those expectations comes to confirm or disconfirm those expectations. We further inquire into the motivational and structural foundations of confirmation and disconfirmation in social interaction, using these inquiries to address frequently asked, but rarely answered, questions about expectations and social interaction. Finally, we argue that investigations of expectations in social interaction provide a paradigm for more general theoretical and empirical considerations of interpersonal processes and social relationships.