The effects of student socioeconomic status (SES) and four teacher behaviors--teacher structure, teacher affect, cognitive level of questions, and group size--on student reading achievement were analyzed. Subjects were 36 fifth and sixth grade classroom teachers and their 820 students. Data were collected with the Reading Comprehension Subtest from the Iowa Tests of Basic Skills, an estimate of SES, and the Georgia Assessment of Teacher Effectiveness (GATE). The results upheld many previous findings, indicating that high SES students scored higher in reading than did low SES students. Although the analyses produced no significant interaction F-ratios, high and low frequency of selected teacher behaviors seemed to make a difference in student reading behavior. Apparently, structured academic time did not produce better reading achievement for either high or low SES students, but structured student behavior had a negative impact, especially on low SES students. Students under the influence of hostile teacher behavior also were negatively affected. Low SES students achieved better with low cognitive level questions. Students who had the opportunity to participate in small group activities, either prescribed or independent, achieved at a higher rate. (RL)