Cronbach’s alpha of externalizing problems ranged from .88 to .92 for mothers on the CBCL, .83 to .89 for fathers on the CBCL, .94 to .96 for the teachers on the TRF, .84 to .92 for self-reports on the YSR, and .83 to .91 for self-reports on the YASR, depending on the year, and was .89 for peers on the YASR. Correlations across raters within-year ranged from .24 to .71 (M = .40, ps < .001), depending on the year measured. Correlations within type of rater across years ranged from .34 to .77 for mothers (M = .61), .29 to .63 for teachers (M = .50), .58 to .79 for fathers (M = .68), and .28 to .81 for self-reports (M = .56; ps < .001) depending on the year. Correlations, means, and standard deviations of the POM-rescaled externalizing problems are in Table 3. Averages of externalizing problems over time by time frame are depicted in Figure 1.
