Results revealed that program participation by probationers improved during the use of RPT, as indicated by higher completion rates compared to a social skills curriculum used the previous year. In additions, persons who successfully completed RPT sessions had lower rates of drug use after RPT (based on urinalysis results) and higher test scores on lesson materials. Finally, the randomly assigned group of probationers who were trained using maps scored significantly higher on knowledge tests administered after each lesson, revealing that the maps aided in enhancing immediate processing and recall of the information presented in the lesson. Results suggest that manual-driven lessons dealing with relapse prevention issues can be used effectively with probationers. Knowledge mapping is also recommended as a technique for enhancing instructional materials. Tables, appended maps, and 12 references (Author abstract modified)