The corrections policies and programs examined are confrontation; area-wide strategies of delinquency prevention; social casework, social agency, and societal or institutional approaches to delinquency prevention; diversion; physical challenge; restitution; group counseling or therapy; individual counseling or therapy; family intervention; vocational training; employment; educational training; behavioral approach; cognitive behavioral; life skills; multimodal approach; probation and parole enhancement; intensive supervision; intensive aftercare supervision; and community-based approaches compared to institutional intervention. In five groups or generic approaches, individual studies had the lowest percentage of successful outcomes (recidivism reduction) or an average effect size that was relatively low: confrontation, areawide strategies of delinquency prevention, diversion, group counseling or therapy, and individual counseling or therapy. Some individual programs within these categories did have records of success, however. The program categories that had the strongest positive results are the behavioral, cognitive behavioral or cognitive, life skills or skill oriented, multimodal, and family intervention. The author also discusses unimodal and combination approaches, as well as research on combinations. A review of the studies of nonprogrammatic factors focuses on staff characteristics, staff- client interactions, offender differences, and setting. A discussion of further challenges in knowledge building addresses the scope of study and the global approach. Appended supplementary information and 48 notes