Twenty-eight second and third grade classrooms in Austin, Texas were observed for approximately thirty hours each, using an elaboration of the Brophy-Good Dyadic Interaction Observation System. These process data were then analyzed for differences according to grade, student sex, and student socioeconomic status (SES). Grade and sex differences were below chance levels in frequency and were generally as would be expected in direction. However, SES differences were widespread, indicating that teachers working at the same grade level may be faced with very different opportunities and demands. High SES classrooms featured eager and competitive students and businesslike teachers who focused on the curriculum. In contrast, low SES classrooms featured students who were fearful, anxious, and generally alienated from the student role. Their teachers attempted to combat student fears with patience and determination, and showed a greater willingness to deviate from the curriculum and to attend to matters of personal concern or interest; they generally exhibited a more personalized approach. These process differences in teacher behavior appeared to be appropriate responses to the particular demands placed upon the teachers. (Author/MV)