Treatment was administered in a modified therapeutic community and 3 months of aftercare. Two counselors per community (four communities of 26-38 probationers are housed at the same time for treatment) provide group counseling, education classes that address life skills, graduate equivalency degree training, and other substance abuse education. Over the course of the study, these communities were randomly assigned to receive mapping-enhanced counseling or standard treatment components. Self-ratings of "working the program" (i.e., conscientiously participating in treatment) were compared with ratings by peers in the program and with ratings by counselors. Peer and counselor ratings were more highly correlated with each other than with client self-ratings. Peer as well as self-ratings detected differences between enhanced and standard counseling and were related to individual-difference measures known to be associated with treatment progress. In addition, peer midterm ratings of "working the program" were related to both self-ratings and counselor ratings of clients' end-term participation, as well as counselor ratings of the likelihood of remaining clean and sober. These findings support the use of peer ratings as additional indicators of treatment progress. 1 table and 30 references