Reevaluating Inter-Rater Reliability in Offender Risk Assessment

Abstract

Offender risk and needs assessment, one of the pillars of the Risk-Need-Responsivity model of offender rehabilitation, usually depends on raters assessing offender risk and needs. The few available studies of inter-rater reliability in offender risk assessment are, however, limited in the generalizability of their results. The present study examined inter-rater reliability in Dutch offender risk assessment of 38 raters who independently assessed 75 offenders. Results show substantial reliability (Tinsley & Weiss’ T value ≥ .61) for risk of reconviction and moderate (T value ≥ .41) to substantial reliability for offender needs, such as accommodation, finances, or education. These results are discussed in light of a recent British study on the inter-rater reliability of a comparable risk assessment instrument. Results from the present study show similar to better reliability, leading to the conclusion that greater external validity does not negatively influence inter-rater reliability results.

Keywords: offender assessment,risk, Inter-rater reliability, recidivism risk assessment scales (RISc)