The Effects of Group Size and Instructional Method on the Acquisition of Mathematical Concepts by Fourth Grade Students

Two hundred twenty-five fourth grade students were assigned to groups of either 1, 3, or 6 students to receive lessons taught in one of three ways: 15 minute teacher- led lesson only; 15 minute lesson plus 12 minutes of teacher-led follow-up; or 15 minute lesson plus 12 minutes of supervised seatwork. Analysis of the posttest achievement scores yielded a significant main effect for method and a significant method by group size interaction. Time-on-task during the lessons varied as a function of group size, with the smaller groups having greater time-on-task; during the follow-up, the supervised seatwork groups of sizes 3 and 6 had greater time-on-task than the teacher-led groups. The seatwork groups had more opportunities to respond during follow-up than the teacher-led groups. The results are discussed in terms of the existing literature on group size and effective instructional variables.