The purpose of this study was to evaluate the effectiveness of an Intensive Probation Supervision (IPS) program on high-risk offenders. The IPS program was characterized by four changes in usual procedures: (1) increased supervision, (2) risk/needs assessment for substance abuse, employment, and marital/family relationships, (3) stricter enforcement of probation, and (4) a four-stage revocation procedure for technical violations. The investigators also studied whether the additional caseload of the probation officers who implemented the IPS program reduced the number of supervision contacts with non-IPS probationers under normal minimum, moderate, and maximum supervision regimens. Offenders put on IPS probation in 1985 from 13 experimental courts were compared to high-risk offenders put on regular probation in the experimental courts in 1984, and to high-risk offenders on regular probation from 13 control courts for both 1984 and 1985. Data were derived from risk assessment forms, needs/strengths assessment forms, probation supervision records, and criminal history data obtained from the state's probation central field. For each offender, a full range of data were collected on (1) offender risk characteristics at initial, four-month, ten-month, and termination assessments, (2) offender needs characteristics at the same intervals, (3) probation officer/offender contact chronologies for the entire one-year follow-up period, and (4) offender prior criminal history and recidivism during a one-year follow-up period.