Modeled after a widely replicated Hawaii probation system reform - Hawaii's Opportunity Probation With Enforcement - features "swift, certain, and fair" sanctioning for probation violations, based on regular monitoring with random drug-testing; for example, a single, relatively minor probation violation, such as a positive drug test or a missed appointment with a probation officer, might warrant a few days of incarceration. Probation status would be restored after release. The HOPE format is intended to reduce procedural uncertainty. uneven justice, and lengthy delays in response to violations. The current evaluation examined HOPE demonstration programs in counties in Arkansas, Massachusetts, Oregon, and Texas. The study divided 1,504 HOPE-eligible individuals into a HOPE treatment group and a control group that received probation as usual. Outcome differences between these groups were measured. The process evaluation found that all sites faithfully implemented the HOPE model; however, the outcome evaluation showed that HOPE probationers proportionately committed significantly more probation violations than members of the control group (89 percent compared to 82 percent), and the number of violations was higher for the HOPE group (3,770 compared to 3,134). These findings may be due to the tighter monitoring requirements under HOPE; however, there was no evidence that close monitoring and rapid and predictable response to probation violations significantly impacted recidivism. Re-arrests were 40 percent for HOPE and 44 percent for controls. Revocation of probation was 25 percent for HOPE participants and 26 percent for controls. The study's report advises that sites considering the implementation of HOPE probation provisions consider these implications of HOPE programs within the context of their current probation policy and practice.