Defining Probability in Sex Offender Risk Assessment

Area of Science:

• Forensic Psychology
• Risk Assessment
• Probability Theory

Background:

• Actuarial scales for sexual recidivism risk prediction are debated.
• Confusion arises from conflating Frequentist and Bayesian probability definitions.
• Frequentist probability is inappropriately applied to individual risk assessment.

Purpose of the Study:

• To clarify the distinction between Frequentist and Bayesian probability.
• To demonstrate how Bayesian probability resolves issues in sex offender risk assessment.
• To advocate for the use of Bayesian probability in individual risk prediction.

Main Methods:

• Review of Frequentist and Bayesian probability concepts.
• Analysis of their application in risk assessment.
• Conceptual framework for applying Bayesian probability to sexual recidivism.

Main Results:

• Frequentist probability is not applicable to single-case predictions.
• Bayesian probability is inherently suited for individual risk assessment.
• The Bayesian framework offers a coherent method for sex offender risk evaluation.

Conclusions:

• The distinction between probability types is critical for accurate risk assessment.
• Bayesian probability provides a robust and coherent framework for predicting individual sexual recidivism.
• Wider adoption of Bayesian methods is recommended for sex offender risk assessment.