This study explored the relationship between changes in student classroom behavior and teacher behavior. More specifically, teacher responses to students were evaluated as a function of systematic changes in the students' classroom behavior. The investigation was conducted in a fifth-grade classroom of a primary school located in a residential, suburban neighborhood. Two disruptive pupils from the class were chosen as target students for the study. The dependent, observable variables were teacher behavior, teacher verbal responses, teacher ranking cards, and subjective unit of irritation. The independent, observable variables was student behavior. The variables were measured by six undergraduates and one teacher. The reliability of the observers was assessed before and after completion of the study. The results showed that changes in the students' classroom behavior had consistent effects on the behavior of the teacher. (Discussion of the results follows, stressing the importance of reward. Two tables of data are included.) (BRB)