A psychometric study of items Level of Service/Case Management Inventory (LS/CMI) with the contribution of classical test theory among offenders Quebec

The purpose of an actuarial instrument is to generate a score or numeric index that can be used to predict the probability of an event. The Level of Service / Case Management Inventory (LS/CMI), which is an inventory of the level of service and the management of cases, is part of the last generation of risk-assessment actuarial tools. The predictive validity studies that have been conducted on tools such as the LS/CMI and the Level of Service Inventory-Revised (LSI-R) could not determine satisfactorily the metrological properties of the items that comprise them. The analysis in the present article fills a gap in the writings of specialists by exploiting scientific advancements in measurement theory to the benefit of criminology. The sample was drawn from evaluations carried out at two different times, February 2007 or March 2008, of two groups: 2,670 inmates and 1,837 people serving sentences in the community. The assessments focused primarily on the 43 items operationalizing the eight components of risk that comprise the structure of Part 1 of the LS/CMI. The results of these assessments have helped target some items that are problematic when it comes to discrimination and redundancy.