IDENTIFYING POSITIVE DISSIMULATION BY SUBSTANCE-ABUSING INDIVIDUALS ON THE PERSONALITY-ASSESSMENT INVENTORY - A CROSS-VALIDATION STUDY

The accuracy of a classification equation (which combined scores on th e Drug Problems, Alcohol Problems, and Positive Impression scales from the Personality Assessment Inventory [PAI], Morey, 1991), developed b y Fals-Stewart (1996) to identify test-taking response sets among subs tance-abusing individuals, was evaluated. As in the Fals-Stewart (1996 ) study, three groups of participants completing the PAI were assessed : (a) substance-abusing patients administered the inventory under stan dard instructions (n = 25); (b) substance-abusing patients asked to re spond defensively (n = 25) combined with a group of individuals suspec ted of abusing drugs, referred for an evaluation by the criminal justi ce system, who had reasons to conceal their drug use (n = 25); and (c) non-substance-abusing respondents administered the test under standar d instructions (n = 25). Significant validity shrinkage in the classif ication equation was found when applied to the new sample; only 68% of participants were correctly classified into their respective groups, compared to 82% of participants correctly assigned in the Fals-Stewart (1996) investigation.