Group contingencies structure situations which link individual behavior with group outcomes, attempting to change behavior through peer pressure. As such, group contingencies raise numerous methodological and ethical problems, and illuminate the relationship between what data is collected and what subsequent decisions can be made. Over 100 published group contingency studies were examined, with key points including: (1) although group contingencies use peer interaction to bring about change, less than half the studies cited reported social interaction or attempted to identify the type of peer pressure operating during the experimental procedure; (2) many of the group contingency studies collected only group data; (3) some group contingency studies are illustrative of potential conflicts between the role of the researcher and the role of the teacher; and (4) the language of group contingencies tends to legitimize their use without considering possible ill-effects. These issues serve to raise substantial questions concerning the advisability of using group contingencies in classrooms and stresses the need to monitor closely the social interactions which occur as a result of their implementation. (Author/BMW)