Regarding a general cost-benefit evaluation approach, the Washington State Institute for Public Policy (WSIPP) first looks at the national criminal justice and prevention evaluation literature and then conducts in-State evaluations of programs. In these evaluations, it attempts to compare program results on a consistent basis while also looking at program costs. The WSIPP's cost-benefit findings on juvenile delinquency prevention programs include the finding that some prevention and intervention programs work with certain groups of people in certain settings and others do not; reasonably-priced programs that can achieve even modest reductions in future crime rates yield positive economic returns; and the largest and most consistent economic returns come from programs designed for juvenile offenders. One panelist explains how to perform a simple cost-benefit analysis of a crime prevention program. A panelist representative from the RAND Corporation presents cost-benefit analysis principles RAND has used to evaluate early childhood intervention programs. RAND research shows that early interventions targeted at disadvantaged families can benefit children and their families and that the savings generated by them can outweigh their costs. A cost-benefit analysis must include both treatment and control groups so that program effects can be isolated. The study also must include an adequate initial sample size, minimal sample attrition over time, and a long follow-up period. Audience questions and discussion are summarized.