Although reoffending differences were not statistically significant for program completers compared with offenders not assigned to the program, there was a trend toward a reduced number of offenses by program completers. There was a 33-percent reduction in the new offense rate among program completers compared to the control group. Differences in reoffending for new technical violations of probation conditions were statistically significant, with program drop-outs having dramatically higher rates of technical violations than either program completers or the control group. Certain factors significantly increased the likelihood of an offender receiving a new technical violation. These factors included being classified as "high risk" on an objective risk assessment instrument, being a program drop-out, and having poorer interpersonal problem-solving skills as measured by the Interpersonal Problem Solving skills Assessment (IPSSA). "Thinking for a Change" is currently used with adult offenders nationwide. It is based in cognitive-behavioral principles and consists of a scripted manual that states the content and objectives of each of its 22 sessions. Most sessions include instruction, role-play illustrations of concepts, a review of previous lessons, and homework assignments in which participants practice skills learned in group sessions. The program aims to identify and change the deficient interpersonal problem-solving skills that underlie offending behaviors. Participants in the evaluation were 142 adult men and women on probation and classified as medium risk, high risk, or high need by their probation officer. The control group consisted of offenders who met admission criteria for the program but who had not yet been referred to it. The drop-out group was composed of those who entered the program but had three to four absences. 2 figures and 32 references