The concept of definition of the situation is rooted in the view that human behavior is affected by the environment only indirectly, via the person's image or cognitive map. As a communication concept, however, definition of the situation must also have a relational aspect; an interaction process depends, in part, on the relationship between the differing definitions of situation of the participants. Ninety undergraduates participated in a study which examined how the coorientation state (relationship between actors' definitions of situation) influenced communication behavior. In particular, the study examined differences between communicative behavior of dyads with low consensus on situational definition, dyads with a minimal definition of the situation, and dyads with a detailed high definition of the situation. An analysis based on McHugh's conceptualization of things said in defining the situation indicated that trends of messages which define the situation are predictable. Implications for further research using this paradigm are discussed. (Author/AA)