Ability × Treatment Interaction Effects on Children's Learning in Large-group and Small-group Approaches

This study investigated ability × treatment interaction effects on students' learning in large-group and small-group teaching approaches. Each of two elementary teachers taught a 2-week geometry unit to two classes of fourth- and fifth-grade students. Each class received one teaching approach. Stratified random assignment was used to assign students to classes. Students completed aptitude measures at the beginning of the study and achievement, attitude, and retention measures at the end. Regression analyses showed a significant curvilinear aptitude-treatment interaction (ATI) for ability that supported previous ATI findings. High- and low-ability students did better in the small-group approach than in the large-group approach. Medium-ability students did slightly better in the large-group approach than in the small-group approach. Analyses of observations of group processes indicated that high- and low-ability students benefited from peer tutoring processes that occurred in the small groups.