Year-long observations of 51 teachers in 11 junior high schools resulted in identification of 2 groups of teachers who were rated as either more or less effective in classroom management during the year. Subsequently, these groups were observed and comparisons were made of their behaviors and activities during the first three weeks of school. After examining narrative and observational data, several broad themes or clusters of variables emerged to differentiate the more and less effective managers. These areas included: (1) rules and procedures; (2) teacher monitoring of student compliance and following through with consequences; (3) establishment of a system of student responsibility or accountability for work; (4) skills for communicating information; and (5) skills in organizing instructional activities. This report presents an analysis of teacher behaviors for each group in each of these areas. Implications of the results for teacher education and research on teaching are discussed. Appended tables provide data on all of the variables measured and compared during the study. (JD)