The research on what works in correctional interventions provides a powerful agenda for correctional programming. Evaluability assessment is a tool that can be used to help put this research into practice by providing a measure of program quality. The article describes Gendreau and Andrews's Correctional Program Assessment Inventory (CPAI) as one example of an evaluability assessment tool that is designed to ascertain how well programs are meeting certain standards of effective intervention. It also reports the results of CPAI's conducted on 86 treatment programs. These programs are not adequately incorporating the principles of effective intervention into their correctional programming. The article discusses common shortcomings in the programming and offers potential resolutions. In conclusion, the article notes that 34.1 percent of the programs were rated "unsatisfactory." On average, programs suffered from a general lack of program integrity. However, the requisite organizational framework appeared to be in place. Program directors and staff members were well qualified and integral to program development, the level of funding was adequate and sustainable, and there was internal and external support for the programs. On the other hand, the majority of programs do not adequately assess offender risk, need, or responsivity factors; do not use effective treatment models; do not use behavioral strategies; do not adequately train staff members; and do not evaluate themselves or the performance of the offenders they serve. Notes, tables, references