Factor-Analytic Evidence for the Complexity of the Delis-Kaplan Executive Function System (D-KEFS)

Area of Science:

• Psychology
• Neuroscience
• Psychometrics

Background:

• Executive functions are crucial cognitive processes underlying goal-directed behavior.
• The Delis-Kaplan Executive Function System (D-KEFS) is a comprehensive battery assessing various executive functions.
• Understanding the factor structure of the D-KEFS is essential for accurate interpretation of its scores.

Purpose of the Study:

• To investigate the complexity of the D-KEFS factor structure.
• To determine the optimal number of factors for modeling the D-KEFS.
• To evaluate factor retention criteria for complex cognitive batteries.

Main Methods:

• Factor analysis of the D-KEFS standardization sample correlations.
• Monte Carlo simulations varying the number of generating factors.
• Evaluation of factor retention criteria including eigenvalues, fit indices, and cross-validation.

Main Results:

• A seven-factor solution demonstrated the best estimation accuracy when generalized to validation samples.
• Modification indices yielded multiple seven-factor solutions with similar fit but divergent factor loadings.
• Results support process overlap theory, indicating complex tests involve numerous distinct executive processes.

Conclusions:

• Executive function tests are complex, reflecting multiple underlying executive processes.
• Interpretation of D-KEFS scores should rely on external evidence (e.g., clinical sensitivity), not solely factor analysis.
• Avoid oversimplified interpretations of executive function test performance based on factor-analytic findings.