Standard psychometric methods were used, including examining marginal and bivariate distributions of variables before dimension reduction techniques were applied. To estimate the underlying factor structure on dichotomous items, non-linear link functions were utilized using Mplus[21]. A number of solutions were examined, including 1, 2, and 3 dimensional solutions and their fit was assessed using standard measures, such as the CFI (Comparative Fit Index), RMSEA (Root Mean Squared Error of Approximation), and SRMR (Standardized Root Mean Square Residual). Properties of the resulting scale(s) were examined using the Kuder-Richardson formula for examining internal scale reliability of a set of dichotomous items.
