From 1992 through 2002, the National Institute of Justice (NIJ) managed 96 evaluation studies that sought to measure the outcomes of criminal justice programs. A methodological review by the United States General Accounting Office (GAO) of 15 of the 96 studies showed that sufficiently sound information about program effects could not be obtained from 10 of the 15. Five studies appeared to be methodologically rigorous in both design and implementation, enabling meaningful conclusions to be drawn about program effects. Six studies began with sound designs but encountered implementation problems that would render their results inconclusive. An additional four studies had serious methodological limitations that from the start limited their ability to produce reliable and valid results. Although results from five completed studies were inconclusive, program administrators said that they found some of the process and implementation findings from them to be useful. The GAO recommends that NIJ review its ongoing outcome evaluation grants and develop appropriate strategies and corrective measures to ensure that methodological design and implementation problems are overcome so the evaluations can produce more conclusive results. Also, it recommends that NIJ assess it evaluation process with the purpose of developing approaches to ensure that future outcome evaluations are funded only when they are effectively designed and implemented. 7 tables, 4 appendices