If correctional evaluation research is to contribute to the accumulation of practical knowledge, it should be designed to test abstract behavioral science principles that explain why a particular type of program should change the future conduct of a specific category of clientele. (Author)

Evaluation of the first Texas correctional substance abuse program indicated that although recidivism was significantly reduced for offenders completing the program, a large number did not complete it and had recidivism rates comparable to those not participating. This problem and others caused the Texas Legislature to decide against expansion.…