The study used the two samples of studies reported by Andrews, Dowden, and Gendreau. The first sample (n=131) contained the juvenile offender studies used in the Andrews and colleagues meta-analysis. The second sample (n=98) included additional studies collected by Andrews and his colleagues after the publication of their 1990 paper, as well as studies gathered by Dowden. The coding manual used for the current study incorporated items taken directly from Andrews and colleagues, several items introduced by Lipsey, and new variables introduced by Dowden. The measure of effect size used for this report was the Pearson product moment correlation coefficient and, more specifically, the Phi coefficient. The findings of this meta-analysis provide strong empirical support for the applicability of the principles of human service, risk, need, and responsivity for young offenders. In addition, increased adherence to these principles is associated with increased reductions in reoffending. These findings suggest that the clinically relevant and psychologically informed approaches to reducing recidivism outlined by many of the scholars of the rehabilitation literature are indeed effective for young offender populations. 11 footnotes