spent drinking/recovering and physical/psychological problems showed DCF by gender but not by DUI status. There was no evidence of DCF for tolerance, withdrawal, or activities given up, and so the IRT parameters for these criteria were constrained across groups in the final model. Results of the final model accounting for these similarities and differences and for differences in factor means are displayed in Table 2, and item characteristic curves (ICCs) representing group differences for criteria with DCF are displayed in Figure 1.
