Progress in the treatment of any disorder requires the development of methods for evaluation as well as the development of potentially effective new treatments. In this chapter we briefly describe a new instrument to be used in the measurement of substance abuse treatment, the Treatment Services Review. Some of the potential problems in evaluation research are discussed, such as the tendency for more severely ill patients to be more willing to give up their right to choose treatment and agree to randomization. These unexpected tendencies in study volunteers limit the generalizability of treatment research. Evaluation techniques are illustrated by two studies comparing inpatient and outpatient rehabilitation. The results for both alcohol dependence and cocaine dependence were positive, but there was no evidence of a significant advantage for one treatment environment over the other. This has important implications for program funding. We also describe our search for a new treatment technique based on a conditioning model for cocaine dependence. Pilot studies suggested an improvement in treatment outcome for the patients receiving the experimental treatment, and therefore, a prospective study with random assignment was conducted.