The purpose of this study was to collect normative data on the reinforcement repertoires of teachers while interacting with lower and middle class students. Previous research suggests that the closer the values and social goals of students and their teachers, the more likely that positive classroom interaction would occur. It was therefore hypothesized that middle class teachers would positively reinforce their middle class students more frequently than their lower class students. Because social class groups respond differently to various kinds of reinforcement, it was hypothesized that those reinforcers which prove most effective for each group would, in time, be recognized and employed by the teachers. Hence, it was expected that verbal reinforcers would be observed more often with middle class students, and non-verbal reinforcers with lower class students. Schedules of teacher reinforcement for lower and middle class, white students were recorded with a systematic observational technique, the Teacher Reinforcement Schedule. Twenty minutes of recordings were made by six observers within each of 24 fifth and sixth grade classes. At both grade levels, classes were equally divided into those with predominantly lower or middle class students. Significantly more total reinforcements were given to middle than to lower class children. (Author/JM)