Chatting to Learn: The Changing Psychology and Evolving Pedagogy ...

In reviewing the literature on small group discussions in the classroom, Cohen (1994) highlights a potential contradiction in identifying factors that promote learning. In her own research on Complex Instruction (e.g., E. G. Cohen, 1984; E. G. Cohen & Lotan, 1995), Cohen has demonstrated that simple measures of on-topic interaction usually correlate with learning gains. In a series of studies on mathematics learning, however, Webb (1991) has shown that on-topic interaction plays only a minor role when compared with the importance of giving and receiving detailed explanations.

To resolve this conflict, Cohen (1994) hypothesizes that the task structure seems to play an important role in determining the relative importance of different behaviors in group learning. In his work on group processes, Steiner (1972) described three types of group to asks: additive, conjunctive, and disjunctive. In additive to asks, all group members perform the same task, and then pool their results. In conjunctive to asks, each group member must uniquely contribute to achieving the group goal. In other words, performance of the group often depends largely on the performance of the weakest member of the group. Disjunctive to asks, however, depend on the strongest member of the group, because they are to asks that require only one individual to identify the best answer (although the other group members must still accept this answer).

Cohen used conjunctive to asks in her studies while Webb focused more on disjunctive to asks. She argues that the outcome of conjunctive to asks depends primarily on interaction, and that the outcome of disjunctive to asks depends on explanation (E. G. Cohen, 1994). Chizhik’s (2001) research on the relationship between social status and task type offers supporting evidence for Cohen’s hypothesis. Specifically, he examined small groups of students—containing one Caucasian male, one Caucasian female, one African-American male, and one African-American female—performing either a conjunctive or a disjunctive task.