The corresponding scale information curves (SICs) for each subscale are overlaid in Fig. 1. Because SICs are an additive function of the number of items contributing to a given scale, they are impressive given that each subscale has only four items. Table 3 shows the total information (area under the curve—AUC) for each SIC for each subscale, and the total information per item. Recall that information in IRT is related to reliability in CTT. This relationship was confirmed in both samples: mean interitem correlations (MICs in Table 2) were correlated with SIC AUCs from the three subscales, rs(1) = .999 and .947 in Sample 1 and 2, respectively.