Factor analyses of the Woodcock-Johnson iv tests of cognitive abilities, tests of achievement, and tests of oral language
Over the past century, the prominent focus on the study of intelligence in the field of psychological science has yielded increased attention. In particular, researchers have created numerous theories and/or models to better understand the concept of intelligence, yet continued disagreement exists in the field. Moreover, methods for efficiently measuring the concept of intelligence remain an ongoing and pressing discussion. In the field of school psychology, healthcare professionals are responsible for understanding the complexities of cognitive functioning, and thus, the importance of structural validity in measures of intelligence is heightened. It is imperative that healthcare professionals are able to effectively interpret the scores provided by a measure of intelligence. Further, it is critical that these measures of intelligence utilized by healthcare professionals measure the cognitive factors they claim to measure. The Woodcock-Johnson IV Tests of Cognitive Abilities (WJ IV COG), Tests of Oral Language (WJ IV OL), and Tests of Achievement (WJ IV ACH) are three testing batteries in the Woodcock-Johnson IV (WJ IV) that purportedly measure general intelligence as well as ten broad cognitive factors: comprehension-knowledge (Gc), fluid reasoning (Gf), short-term working memory (Gwm), long-term storage and retrieval (Glr), visual processing (Gv), auditory processing (Ga), processing speed (Gs), reading and writing (Grw), quantitative knowledge (Gq), and domain-specific knowledge (Gkn). Research supporting the factor structure of the WJ IV is inconclusive, thus raising the question as to whether the WJ IV cognitive factors as claimed by the test authors. The primary purpose of this study was to examine the factor structure of the WJ IV using differing models of cognitive ability. Specifically, this research study examined whether the CHC Theory of Intelligence or the Functional CHC Model of Cognitive Abilities best fits the standardization data from the WJ IV Norming Study. The data analyses incorporated multiple exploratory factor analyses (EFA) and confirmatory factor analyses (CFA) of the WJ IV standardization data for school-age individuals (e.g., age 6 to 19). Results from this study indicate that the factor structure of the WJ IV, as well as the composition of tasks on the assessment battery, deviate from what is presented in the Technical Manual (McGrew, LaForte, & Schrank, 2014). Results from this study also provide support for some of the hypothesized groupings of broad and narrow abilities posited by the F-CHC Model. Finally, results from this study suggest that in comparison to the CHC Theory of Intelligence, the Functional CHC Model of Cognitive Abilities best fits the data from the WJ IV standardization sample.