Effect sizes in the treatment of sexual offenders.

This article considers the benefits of sexual offender treatment in terms of the magnitude of the effect size produced by these interventions. Comparisons are made of the effect sizes with those generated by treatment of other offenders, by treatment for mental health problems, and by treatment for physical health problems. In all cases, effect sizes with sexual offenders are comparable to (and in some cases better than) effect sizes for the treatment of the other groups. As a final note, it is suggested that using a harm reduction index to estimate effect sizes for treatment with sexual offenders would produce more meaningful results.