Parallel analysis based on minimum rank EFA performed in the development sample recommended the extraction of a single factor for the Internalizing Scale, suggesting unidimensionality. Factor loadings for the EFA are reported in Table 3. CFA in the validation sample confirmed these findings. Single-factor models had good fit, as indicated by RMSEA smaller than 0.05 and CFI bigger than 0.95. ECV was bigger than 0.81 both in the development and the validation samples; that is, more than 81% of the common variance in its items was explained by a single general factor. A two-factor model showed goodness of fit (by means of the RMSEA and CFI statistics) similar to the single-factor model, but with a considerably larger BIC (i.e., single-factor BIC = 143.29 vs two-factor BIC = 156.90). Parallel analysis did not support the two-factor model either.
