Specific interests were participants' rates of recidivism and changes in frequency of disciplinary actions prior to, during, and after participation while incarcerated. TIS participants (n=360) were matched with non-participating cohorts on the variables of age, race, gender, type of offense (property, violent of other), facility/location, and length of sentence. Level of participation was controlled for by dividing the participants into four categories: 1-15 credit hours, 16-39 credit hours, 40 plus credit hours, and graduates. Statistically significant differences were found at all levels of comparison between participants and non-participants: The TIS participants had lower projected recidivism rates than the matching group. However, there was no apparent cumulative effect of participation. The survivorship of participants who completed 15 hours or less of instruction was similar to those who had completed 40 or more hours of instruction. Two variables (employment history and educational level at reception) were not available in automated form, thus precluding matching on them. The disciplinary action phase of the study involved examination of hard-copy records. From these records employment history and educational level were found to be significantly different for participants: (69 percent employed at reception for participants, compared with 48 percent for non-participants; and 28 percent of participants with some college work, compared with 16 percent for non-participants.) No differences in disciplinary actions taken before, during, or after participation were found when participants (n=100) were compared with matched non-participants. Due to the two uncontrolled variables (employment and education level) and the lack of a cumulative effect across levels of participation, causal inferences regarding participation and recidivism, cannot be made. It may be that participation in TIS is an indicator of some other underlying difference among inmates. (Author abstract)