Selection Procedures

The results reported here were derived by updating a previously conducted meta-analysis of the effects of intervention on delinquency (Lipsey, 1992, 1995) with more recent studies. A subset of studies on serious offenders was selected from that meta-analysis, yielding 200 experimental or quasi-experimental studies of interventions for both noninstitutionalized and institutionalized serious offenders. The studies selected for the new database had the following characteristics:

• The great majority, or all, of the juveniles were reported to be adjudicated delinquents. Most had records of prior offenses that involved person or property crimes or other, more serious, acts of delinquency (but not primarily substance abuse, status offenses, or traffic offenses).
  
  
• The referral to the intervention program was made by someone within the juvenile justice system, or the juveniles were recruited directly by the researcher.

Other studies included were those in which most or all of the juveniles in the study had aggressive histories or those whose specific purpose was to change aggressive juvenile behavior.

Effective Intervention for Serious Juvenile Offenders	Juvenile Justice Bulletin • April 2000