Interpretation of KABC-II scores: An evaluation of the incremental validity of Cattell-Horn-Carroll (CHC) factor scores in predicting achievement.

Abstract

This study is an examination of the incremental validity of Cattell-Horn-Carroll (CHC) factor scores from the Kaufman Assessment Battery for Children-second edition (KABC-II) for predicting scores on the Kaufman Test of Educational Achievement-second edition (KTEA-II). The participants were children and adolescents, ages 7-18, (N = 2,025) drawn from the KABC-II standardization sample. The sample was nationally stratified and proportional to U.S. census estimates for sex, ethnicity, geographic region, and parent education level. Hierarchical multiple regression analyses were used to assess for factor-level effects after controlling for the variance accounted for by the full scale Fluid-Crystallized Index (FCI) score. The results were interpreted using the R2/ΔR2 statistic as effect size indices. Consistent with similar incremental validity studies, the FCI accounted for statistically and clinically significant portions of KTEA-II score variance, with R2 values ranging from .30 to .65. KABC-II CHC factor scores collectively provided statistically significant incremental variance beyond the FCI in all of the regression models, although the effect size estimates were consistently negligible to small (Average ÄRCHC2 = .03). Individually, the KABC-II factor scores accounted for mostly small portions of achievement variance across the prediction models, with none of the individual CHC factors accounting for clinically significant incremental prediction beyond the FCI. Additionally, most of the unique first-order predictive variance was captured by the Crystallized Ability factor alone. The potential clinical and theoretical implications of these results are discussed.

Assessing the Incremental Value of Kabc-Ii Luria Model Scores in Predicting Achievement: What Do They Tell Us Beyond the Mpi?

“…These results are similar to previous findings (McGill, ) with the alternative CHC interpretive model. However, direct comparison with the incremental validity results from McGill () showed that in the present study, the combined KABC‐II Luria factor scores provided less incremental prediction of the KTEA‐II Reading Comprehension score at ages 13 to 18 years (2%) and the Oral Language Composite across the school‐age span (1%–3%). In contrast, increased prediction was observed for Written Expression at ages 13 to 18 years.…”

“…With respect to the KABC‐II, McGill () utilized similar procedures to assess the incremental predictive validity of the CHC model scores and found that whereas the Fluid‐Crystallized Index (FCI) accounted for clinically significant portions of criterion achievement variance, the CHC factor scores accounted for trivial portions of achievement after controlling for the effects of the FCI. Again, these results are not useful for making inferences about the clinical utility of Luria model scores because the measurement model for that interpretive scheme differs from the CHC model.…”

Re(Examining) Relations between CHC Broad and Narrow Cognitive Abilities and Reading Achievement

“…Whereas, related predictive validity studies with cognitive measures (e.g., Benson, Kranzler, & Floyd, 2016;Canivez, 2013a;McGill, 2015aMcGill, , 2015bMcGill & Spurgin, 2016) have largely suggested that broad and narrow cognitive abilities account for trivial portions of achievement after controlling for general ability, the present results suggest that this conclusion as a general rule may be overstated. As previously mentioned, although the GIA consistently accounted for large reading effects, lower-order scores accounted for meaningful incremental prediction in several circumstances.…”

“…Incremental validity studies using HMRA have been conducted previously on the WJ III COG (McGill, 2015a;McGill & Busse, 2015) and other related intelligence tests (e.g., Canivez, 2013a;McGill, 2015b;McGill & Spurgin, 2016). Across these studies, it was consistently demonstrated that the omnibus full scale IQ score accounted for most of the reliable achievement variance that could be predicted in the regression models and that little additional incremental variance was accounted for by the lower-order broad and narrow ability scores after controlling for the predictive effects of the general factor.…”

Wechsler Individual Achievement Test–Third Edition Oral Language and Reading Measures Effects on Reading Comprehension in a Referred Sample

“…For instance, previous evaluations of earlier additions of the WIAT have noted minimal effects for cognitive index scores above and beyond strong effects from the FSIQ on achievement (Glutting et al, 2006). These findings hold true for the WJ-III (McGill, 2015a; McGill & Busse, 2015) and the KABC-2 (McGill, 2015b). The inclusion of the FSIQ, such as from the Wechsler Intelligence Scale for Children–Fifth Edition (WISC-V; Wechsler, 2014) may affect these results in a similar manner.…”