Seventy-seven fourth- and fifth-grade students were placed in either a cooperative or a competititve learning structure and the teacher either supported or did not support their decision-making competence. As hypothesized, students whose teacher supported them indicated that they were more confident and committed to making a classroom decision than were students whose teacher did not support them. Unexpectedly, students whose teacher did not support them indicated that they felt they had gained more peer support than students whose teacher did support them. Students in the cooperative learning structure indicated that they had more peer support and had higher expectations about the decision-making experience. They did not indicate significantly greater confidence or commitment to making the decision than did students in the competitive learning structure. Results were interpreted as suggesting that teacher support and cooperative interaction can help students develop more favorable attitudes toward opportunities to make classroom decisions. (Author)