Additionally, a cognitive-behavioral training program--- focused on the reduction of aggression and the improvement of social-control--- proved very effective for behavior-disordered adolescents. The program consisted of 12 half-hour sessions over three weeks, during which participants received cognitive-behavioral training and positive reinforcement for learning and using key skills. Sessions were designed to have clear objectives and structured lectures. In post-test data from the program's experimental evaluation, program participants were rated as having significantly more self-control and observed as having significantly fewer aggressive behaviors than youth in the control group. The study sample consisted of 30 behavior-disordered adolescents, equally divided between the treatment and control groups (Etscheidt, 1991).