The Woodcock-Johnson IV Tests of Achievement Provides Too Many Scores for Clinical Interpretation

The Woodcock-Johnson Tests of Achievement, Fourth Edition (WJ IV ACH) is purported to align with Cattell–Horn–Carroll (CHC) theory and offers upward of 20 scores within its interpretive and scoring system. The Technical Manual does not furnish validity evidence for the scores reported by the scoring system, suggesting that evidentiary support may be incomplete. Exploratory bifactor analysis (EBFA; maximum likelihood extraction with a bigeomin [orthogonal] rotation) was applied to the two school-aged correlation matrices at ages 9 to 19. Results indicated nonalignment with CHC theory and do not support the interpretation of most of the scores suggested by the scoring system. Instead, the results of this study suggest that the loading patterns diverge significantly from the interpretive system produced by the WJ IV ACH. Only the academic fluency and academic knowledge clusters emerged following the use of EBFA. Implications for clinical interpretation of the WJ IV ACH are offered.