Evaluator differences in Psychopathy Checklist-Revised factor and facet scores

Area of Science:

• Forensic Psychology
• Clinical Psychology
• Psychometrics

Background:

• The reliability of forensic assessment tools, such as the Hare Psychopathy Checklist-Revised (PCL-R), may be lower in field applications compared to controlled research settings.
• Variability in PCL-R scores in applied settings is often attributed to differences among evaluators rather than characteristics of the individuals being assessed.

Purpose of the Study:

• To investigate the extent of evaluator differences in scoring the PCL-R.
• To examine whether PCL-R training influences scoring consistency among evaluators.

Main Methods:

• Analysis of PCL-R scoring data from 558 offenders evaluated by 14 independent evaluators.
• Statistical control for offenders' self-reported antisocial traits to isolate evaluator effects.
• Comparison of scoring variability between evaluators with and without formal PCL-R training.

Main Results:

• Significant evaluator differences were observed in scoring each PCL-R factor and facet, even after accounting for offender traits.
• A reduction in evaluator scoring differences was noted among the subset of 11 evaluators who had completed PCL-R training.
• These findings suggest that evaluator variability is a notable factor in field assessments.

Conclusions:

• While PCL-R training appears beneficial in enhancing scoring consistency, evaluator differences can still be present in real-world forensic settings.
• The study underscores the importance of evaluator training and standardization in forensic psychological assessments to improve reliability.