Uniqueness and general factor characteristics of the Woodcock-Johnson Tests of Cognitive Ability-Revised

Abstract When new or revised intelligence batteries are published, it is important to know the general factor loading and uniqueness information of the individual tests prior to using them for clinical interpretation. This study investigated the general factor and uniqueness characteristics of the individual tests of the Woodcock-Johnson Test of Cognitive Ability-Revised (WJTCA-R), a revised and expanded version of the 1977 Woodcock-Johnson Test of Cognitive Ability. The subjects were drawn from the nationally representative WJTCA-R standardization sample and were organized into 18 different age categories. Only 2 (Incomplete Words and Visual Closure) of the 19 WJTCA-R tests examined had low general factor loadings. The remaining 17 tests had medium or high general factor loadings. Only 2 (Cross Out and Listening Comprehension) of the 19 WJTCA-R tests had low uniqueness. All other tests had medium or high uniqueness. The implications for clinical interpretation are discussed.