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Classification Accuracy of Actuarial Risk Assessment Instruments
Author(s) -
Neller Daniel J.,
Frederick Richard I.
Publication year - 2013
Publication title -
behavioral sciences and the law
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.649
H-Index - 74
eISSN - 1099-0798
pISSN - 0735-3936
DOI - 10.1002/bsl.2047
Subject(s) - recidivism , risk assessment , computer science , actuarial science , actuarial analysis , statistics , risk analysis (engineering) , psychology , mathematics , medicine , psychiatry , computer security , surgery , business , mitral valve
Users of commonly employed actuarial risk assessment instruments (ARAIs) hope to generate numerical probability statements about risk; however, ARAI manuals often do not explicitly report data that are essential for understanding the classification accuracy of the instruments. In addition, ARAI manuals often contain data that have the potential for misinterpretation. The authors of the present article address the accurate generation of probability statements. First, they illustrate how the reporting of numerical probability statements based on proportions rather than predictive values can mislead users of ARAIs. Next, they report essential test characteristics that, to date, have gone largely unreported in ARAI manuals. Then they discuss a graphing method that can enhance the practice of clinicians who communicate risk via numerical probability statements. After the authors review several strategies for selecting optimal cut‐off scores, they show how the graphing method can be used to estimate positive predictive values for each cut‐off score of commonly used ARAIs, across all possible base rates. They also show how the graphing method can be used to estimate base rates of violent recidivism in local samples. Copyright © 2013 John Wiley & Sons, Ltd.