The first study by Davis, Hoffman, and Quigley concluded that delinquents who successfully completed a PPC residential treatment program rated themselves as having a more positive self-concept upon discharge. The second study by Wasmund found that students from peer group agencies reported greater satisfaction with their social climates than their non-peer-group contemporaries, and staff/student perceptions were more congruent in the peer group agencies than in the non-peer-group agencies. These two studies raise the question of what might be the relative effectiveness of PPC methodology in different settings and in contrast to other specific methods of treatment. Another question might be what program elements actually produce the change. Criticisms of residential treatment of children include the high degree of restrictiveness inherent in residential placement and the expense of residential treatment. 3 references.