By Madeline M. Carter, and The Honorable Richard J. Sankovitz

Isaac Newton was among the first modern scientists to recognize that new discoveries depend heavily on science that is already established: “If I have seen further,” he wrote, “it is by standing on the shoulders of giants.”1 Giant strides have been made in the fields of public administration and criminal justice by applying science to practice. Evidence-based decision making asserts that public policy and practice should be informed by the best available research and enhanced through ongoing performance measurement and evaluation. Scientific study has demonstrated that recidivism can be reduced when three key principles are followed: n The risk principle suggests that justice system interventions should be matched to offenders’ risk level, focusing more intensive interventions on moderate and high risk offenders. n The need principle asserts that justice system interventions should target those factors that most significantly influence criminal behavior. n The responsivity principle demonstrates that interventions are most effective when they are based on research-supported models and tailored to the unique characteristics of individual offenders. In this paper, we propose to take this knowledge one step further: to link the duration of probation supervision to the optimal amount of intervention an offender needs in order to reduce risk of reoffense. The proposed “dosage” model of probation suggests that the length of supervision should be determined by the number of hours of intervention necessary to reduce risk, rather than an arbitrarily (or customarily) established amount of time (e.g., 3 years, 5 years). For many offenders, the research shows that correctional intervention is analogous to treating a patient: too little intervention and the patient receives little or no benefit; too much, and the treatment is ineffective or even harmful.2 Given this, we postulate that the length of supervision should depend on how long it takes an offender to achieve the dosage target—the type and amount of intervention that research tells us he or she needs in order to maximize the potential for behavior change and that is necessary in order to minimize risk to the public—rather than a fixed term of supervision.

Silver Spring, MD: Center For Effective Public Policy , 2014. 22p.