The first step of analyses was to select items from the Project MATCH dataset that corresponded to each stage of Jellinek’s model of the developmental course of alcoholism. Table 1 describes the items used in the continuum, as well as the instrument from which they were drawn and the corresponding stage in Jellinek’s model. One additional developmental marker (visual distortions) was chosen because it corresponded to an item in the Krueger et al. (2004) study, and was thus judged to be important for an alcohol severity continuum, even though it was not in Jellinek’s model. Satisfactory items could not be identified for three of Jellinek’s developmental stages: increased frequency of blackouts, changed drinking patterns, and jealousy. Twenty-four DrInC items, 1 SCID item, and 12 AUI items were selected based on content analyses to represent stages from Jellinek’s model. Of the 12 AUI items, 8 were polytomous, and these items were dichotomized according to the description of the corresponding stages by Jellinek by two independent raters for the purposes of IRT modeling. Raters independently agreed on 7 out of 8 of
