Utility of the Inventory of Legal Knowledge in detecting feigning

The Inventory of Legal Knowledge (ILK) is an instrument designed to detect feigning of competency-specific knowledge deficits. Available studies have suggested the ILK may require modification of its cut score to more accurately classify those who are feigning. In this study, the ILK’s concurrent validity and cut scores were tested using 100 college students in a simulation design. Students were randomly assigned to fake (n = 50) or honest (n = 50) groups. Those assigned to the faking group had significantly lower ILK scores than individuals responding honestly with a large effect size between the groups. Despite some promising results, utility estimates indicated an unacceptable level of false positives using the recommended cut score. Tentative recommendations are made in order to improve the efficacy of the ILK in detecting feigning legal knowledge.     

Competence-Related Abilities and Psychiatric Symptoms: An Analysis of the Underlying Structure and Correlates of the MacCAT-CA and the BPRS

The current study used confirmatory factor analysis to examine the factor structures of two instruments commonly used in the assessment of competency to stand trial--the MacArthur Competence Assessment Tool--Criminal Adjudication (MacCAT-CA) and the Brief Psychiatric Rating Scale (BPRS). Results revealed support for the three-subscale factor structure of the MacCAT-CA defined by the authors of the instrument; for a slightly altered three-factor structure defined by Zapf, Skeem, and Golding (2005, Psychological Assessment, 17, 433-445); and for the four symptom clusters of the BPRS as defined by Hedlund and Vieweg (1980, Journal of Operational Psychiatry, 11, 48-63). In addition, exploratory factor analysis of all 24 items of the BPRS revealed a five-factor structure. Correlations between psychiatric symptoms, symptom clusters, and competence-related abilities were also examined using the previously identified and the newly identified factor structures of the MacCAT-CA and the BPRS. Significant relations between symptoms and psycholegal abilities are discussed.