Three validating variables represent measures of alcohol severity. These include Alcohol Involvement (as measured by an additive AUI scale), Alcohol Dependence, and an Alcohol Typology differentiating individuals who were thought to be vulnerable and severe from those who were not. Notably, alcohol involvement and the typology use items from the AUI and DrInC, respectively, which were used to mark severity in this study. As such, validity comparisons involving the IRT-based measure and these additive indicators represent tests of the hypotheses that organizing information from these instruments in a theoretically-driven manner increases their utility.
