Small-group composition and peer effects

This paper reviews research on grouping of students within classes and its effects on learning. Primary consideration is given to grouping and mixing students by ability, though consideration is also given to grouping and mixing students by ethnicity and gender as well as to research on the effects of group size. Results of meta-analyses of grouping show a small but meaningful advantage of forming students into groups for instruction as compared to using whole-class instruction. In teacher-led, homogeneous ability groups, peer effects result from the normative environment to the extent that peers contribute to norms for behavior, constructed through cycles of reciprocal teacher–student interaction. In peer-led, heterogeneous ability groups, peer effects stem directly from group interactions and discourse among students that lead to cognitive restructuring, cognitive rehearsal, problem solving, and other forms of higher-level thinking. Similarly, in groups of different ethnic and gender composition, peer effects stem from interactions among students according to their perceived status and relative influence within the groups. We argue that these peer influences interact with instructional processes to mediate the effects of group composition on students’ learning. r 2003 Elsevier Ltd. All rights reserved. Grouping and mixing students by ability represent different ways teachers cope with diversity within the classroom. Placing students into homogeneous groups on the basis of ability allows, at least in theory, teachers to reduce the diversity so they can provide appropriate challenges and support to meet the needs of individual students. Students’ membership in the groups can be adjusted to reflect changes in their knowledge and skills. Placing students into heterogeneous groups allows teachers to capitalize on the diversity so they can use peers as resources to support learning. Students can engage in activities such as ‘‘orally rehearsing material, ARTICLE IN PRESS *Corresponding author. Tel.:+1-614-292-8716; fax: +1-614-292-4260. E-mail address: [email protected] (I.A.G. Wilkinson). 0883-0355/03/$ see front matter r 2003 Elsevier Ltd. All rights reserved. doi:10.1016/S0883-0355(03)00014-4 explaining material to others, discovering solutions, and debating and discussing content and procedural issues’’ (Lou et al., 1996, p. 425). Peer-led cooperative groups also reduce demands on teachers’ time, allowing them to concentrate on students who need special assistance and attention. We regard grouping as important for student learning not because of its direct influence but because of its shaping force on instruction and students’ social participation (cf. Dreeben, 1984; Hallinan, 1988). This view is consistent with both sociocognitive and sociocultural perspectives on learning. From a sociocognitive perspective, learning is a cognitive process embedded in social contexts, so both social and cognitive factors influence the outcomes of learning processes (Langer, 1987; Rogers, 1987; Tierney & Rogers, 1989). Setting up groups in the classroom sets in motion social processes that have both social and instructional effects (Rosenbaum, 1980). From a sociocultural perspective, learning is socially constructed during interaction and activity with others, so there is interdependence of social and individual processes in the co-construction of knowledge (Vygotsky, 1978). The contexts in which teaching and learning occur are critical and learning is culturally and contextually specific (Palincsar, 1998). From this perspective, groups can be viewed as sites for changing students’ participation within communities of practice (cf. Lave, 1991; Rogoff, Matusov, & White, 1996). In this paper, we examine the extent to which the grouping of students within classes affects their learning processes and outcomes. Most research has concentrated on ability composition so we give primary consideration to grouping and mixing students by ability. However, we also consider research on grouping and mixing students by ethnicity and gender, as well as research on the effects of group size. Where effects are found, we attempt to determine the extent to which peer effects are implicated and how they might operate. In the latter part of the paper, we develop a model that locates peer influences in the normative and comparative reference-group processes and in the nature of the group interaction and discourse. We argue that these peer influences interact with instructional processes to mediate the effects of group composition on students’ learning. 1. Grouping and mixing students by ability We begin by examining research that has simply examined ability group composition in relation to student achievement. We then review research that examines more closely how group composition is related to instruction and students’ social participation.