An exploratory factor analysis of the Woodcock-Johnson IV Tests of Cognitive Abilities and Tests of Oral Language for the 14 to 19 year old age range

Not only has intelligence been an elusive construct, but methods for measuring it continue to be hotly debated in present day. A multitude of theories currently exist that attempt to objectively explain the mechanisms of intelligence, but the fact remains that any discussion regarding intelligence is theoretical in nature. In an attempt to understand the concept of general intelligence, numerous psychologists and researchers have attempted to quantitatively define this intangible paradigm through various forms of assessment. Accurate test interpretation centers around how well a test measures the construct it contends to measure. The Woodcock-Johnson IV Tests of Cognitive Abilities (WJ IV COG) and Tests of Oral Language (WJ IV OL) are two testing batteries in the Woodcock-Johnson IV (WJ IV) that purportedly measure general intelligence as well as seven broad cognitive factors. The publishers of the WJ IV denote that this most recent iteration of the test is based on modern Cattell-Horn-Carroll (CHC) theory as well as advances in neuropsychological research. Of concern, the WJ IV Technical Manual is exceedingly complex and the results from the presented studies supporting the factor structure of the WJ IV are profoundly obscured for the general practitioner. The primary purpose of this study is to provide an objective analysis of the WJ IV COG and WJ IV OL for the 14- to 19- year old age group to determine the factor structure of the assessment battery. Data analyses included an exploratory factor analysis utilizing the correlation matrix provided in the technical manual by the test publishers. Results from this study indicate the WJ IV COG and WJ IV OL measure five broad CHC factors in the identified age range: comprehension knowledge (Gc), short-term working memory (Gwm), auditory processing (Ga), processing speed (Gs), and a final factor that incorporates fluid reasoning (Gf), long-term storage and retrieval (Glr), and visual processing (Gv) together.