Investigating the Latent Structure of Executive Function in the Delis-Kaplan Executive Function System Using Cattell-Horn-Carroll Theory.

OBJECTIVE: To replicate a seven-factor model previously reported for the Delis-Kaplan Executive Function System (D-KEFS).

METHOD: This study used the D-KEFS standardization sample including 1,750 non-clinical participants. Several seven-factor models previously reported for the D-KEFS were re-evaluated using confirmatory factor analysis (CFA). Previously published bi-factor models were also tested. These models were compared with a three-factor a priori model based on Cattell-Horn-Carroll (CHC) theory. Measurement invariance was examined across three age cohorts.

RESULTS: All previously reported models failed to converge when tested with CFA. None of the bi-factor models converged after large numbers of iterations, suggesting that bi-factor models are ill-suited to represent the D-KEFS scores as reported in the test manual. Although poor fit was initially observed for the three-factor CHC model, inspection of modification indices showed potential for improvement by including method effects via correlated residuals for scores derived from similar tests. The final CHC model showed good to excellent fit and strong metric measurement invariance across the three age cohorts with minor exceptions for a subset of Fluency parameters.

CONCLUSIONS: CHC theory extends to the D-KEFS, supporting findings from previous studies that executive functions can be integrated into CHC theory.