The Effects of Sanction Intensity on Criminal Conduct - JDAI Helpdesk

independence <strong>of</strong> data (i.e., the model parameters were not derived from the same sample
for which predictions would then be made).
This helps to determine whether the
relationships found in the initial sample are generalizable to other members <strong>of</strong> the same
population. Once the model has been specified, it may then be used to derive risk
predictions for probationers in current caseloads.
<strong>The</strong> model assigns each probation case (not each <strong>of</strong>fender) a ‘reliability score’ to
indicate its risk level. <strong>The</strong> reliability score is a value between 0 and 1. <strong>The</strong> selected
threshold for low-risk cases was 0.5, so that cases with a reliability score greater than 0.5
were designated as low risk and scores equal to or less than 0.5 were not low risk. A
specific <strong>of</strong>fender’s risk score is based on the average reliability score across all his or her
active probation cases. However, even if the average reliability score exceeded 0.5, an
<strong>of</strong>fender could not be designated low risk if any one <strong>of</strong> his or her active cases scored 0.5
or below.
<strong>The</strong> Philadelphia model meets many <strong>of</strong> the recommendations set out by Bonta
(2002) and Gottfredson and Moriarty (2006) for optimal risk prediction. Bonta suggests
that risk assessments require predictive validity, direct relevance to criminal behavior and
the correctional setting, and should adhere to the principle <strong>of</strong> the least restrictive
alternative. <strong>The</strong> Philadelphia model is validated by its development on a training sample
<strong>of</strong> cases for which outcomes were already known and its application to other members <strong>of</strong>
the same population. <strong>The</strong> present paper attempts to further validate its ability to predict
who will be low risk. <strong>The</strong> model’s focus on serious <strong>of</strong>fending is directly relevant to
correctional priorities. Finally, the express purpose <strong>of</strong> the model is to ensure that the
most intensive supervision and treatment is only reserved for those who need it most.
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