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Published on: September 16, 2022
Interrater Reliability of Risk Matrix 2000/s.
Helen C Wakeling1, Ruth E Mann, Rebecca J Milner
1National Offender Management Service, London, United Kingdom.
Summary
This study found good interrater reliability for the Risk Matrix 2000/s tool used in sexual offender risk assessment. However, specific factors can impact scoring reliability, suggesting strategies for improvement in practice.
Area of Science:
- Forensic Psychology
- Criminology
- Psychometrics
Background:
- Actuarial risk assessment instruments are crucial for high-stakes decisions regarding sexual offenders.
- Ensuring the reliability and validity of these tools is paramount for accurate assessments.
- Understanding factors influencing reliability is essential for practitioners.
Purpose of the Study:
- To examine the interrater reliability of the Risk Matrix 2000/s.
- To identify factors affecting the reliability of scoring in a real-world setting.
- To propose strategies for enhancing the reliability of actuarial tools.
Main Methods:
- Assessed interrater reliability using one field rater and one independent rater.
- Utilized a sample of over 100 sexual offenders.
- Calculated various reliability statistics within a practitioner context.
Main Results:
- The Risk Matrix 2000/s demonstrated good interrater reliability.
- Reliability varied across different items within the instrument.
- Several factors were identified that appear to reduce scoring reliability.
Conclusions:
- The Risk Matrix 2000/s is a reliable tool for sexual offender risk assessment.
- Awareness of item-specific reliability and influencing factors is necessary.
- Implementing suggested strategies can improve the reliability of actuarial tools in practice.
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