Investigating the Theoretical Structure of the Differential Ability Scales—Second Edition Through Hierarchical Exploratory Factor Analysis

Abstract

When the Differential Ability Scales-Second Edition (DAS-II) was developed, the instrument's content, structure, and theoretical orientation were amended. Despite these changes, the Technical Handbook did not report results from exploratory factor analytic investigations, and confirmatory factor analyses were implemented using selected subtests across the normative age groups from the total battery. To address these omissions, the present study investigated the theoretical structure of the DAS-II using principal axis factoring followed by the Schmid-Leiman procedure with participants from the 5-to 8-year-old age range to determine the degree to which the DAS-II theoretical structure proposed in the Technical Handbook could be replicated. Unlike other age ranges investigated where at most 14 subtests were administered, the entire DAS-II battery was normed on participants aged 5 to 8 years, making it well suited to test the full instrument's alignment with theory. Results suggested a six-factor solution that was essentially consistent with the Cattell-Horn-Carroll (CHC)-based theoretical structure suggested by the test publisher and simple structure was attained. The only exception involved two subtests (Picture Similarities and Early Number Concepts) that did not saliently load on a group factor. Implications for clinical practice are discussed.

Factor structure of the WISC‐V in four standardization age groups: Exploratory and hierarchical factor analyses with the 16 primary and secondary subtests

“…The superiority of general intelligence observed in all four age groups is identical to that found by Canivez et al. () with the total WISC‐V standardization sample and similar to other studies of Wechsler scales using both EFA and CFA methods (Bodin et al., ; Canivez, ; Canivez & Watkins, , ; Canivez et al., ; Dombrowski, Canivez, & Watkins, 2018; Gignac & Watkins, ; Lecerf & Canivez, ; McGill & Canivez, , ; Nelson et al., ; Watkins, ; ; Watkins & Beaujean, ; Watkins et al., , , ) and other intelligence tests (Canivez, ; Canivez & McGill, ; Canivez et al., ; Cucina & Howardson, ; DiStefano & Dombrowski, ; Dombrowski, , , ; Dombrowski & Watkins, ; Dombrowski et al., ; Dombrowski, Golay, McGill & Canivez, ; Dombrowski, McGill, & Canivez, , , ; Dombrowski, McGill, Canivez & Peterson, ; Nelson & Canivez, ; Nelson et al., ). These results are also consistent with the broader professional literature on the importance and dominance of general intelligence (Deary, ; Jensen, ; Lubinski, ; Ree et al., ).…”

Factor Analysis and Variance Partitioning in Intelligence Test Research: Clarifying Misconceptions

“…From this review, they made several unsubstantiated claims that are used to support their premises. For example, Decker and colleagues asserted that “no justification was given for the preference of a BF/SL model” (p. 4) for the Differential Abilities Scales, Second Edition (DAS-II; Elliot, 2007) exploratory factor analysis (EFA) conducted by Dombrowski, McGill, Canivez, & Peterson (2019). This characterization is inaccurate.…”

Don’t Use a Bifactor Model Unless You Believe the True Structure Is Bifactor

“…Dombrowski et al (2020) claim “...ample justification…” (p. 3) has been given in previous studies for using a BF model and SL procedure, and specifically referenced pages 92–93 in Dombrowski, McGill, Canivez, and Peterson (2019) as providing such justification. Readers are encouraged to independently verify this claim; however, the theoretical justification from this reference is difficult to discern.…”

“…Rather, the use of a BF model or SL procedure has primarily been justified by noting the omission of these methods in validity studies reported in technical manuals. For example, in noting the omission, Dombrowski et al (2019) suggested the DAS-II technical manual and theoretical structure was “…presently incomplete.” (p. 93). Often embedded as an argument for including both exploratory and confirmatory factor analytic approaches, previous studies are cited (i.e., Canivez & McGill, 2016) as finding structural validity evidence discrepant from results reported in technical manuals.…”