Factorial Validity of the German KABC-II at Ages 7 to 12 in a Clinical Sample: Four Factors Fit Better than Five

Multidimensional intelligence test batteries such as the KABC-II are widely used in clinical practice. Although validity evidence should be provided for all intended uses of a test, data on the factorial validity of the KABC-II mostly relies on the standardization samples and raises some concerns about the adequacy of the factor structure. Confirmatory factor analyses of the KABC-II core subtests were conducted in a sample of 627 children who had been assessed in German Centers for Social Pediatrics. The standard structure of the KABC-II was superior to unidimensional models but, as in previous research, evidenced cross-loadings and a high correlation between Planning/Gf and Simultaneous/Gv. Pattern Reasoning was more closely related to Simultaneous/Gv than to Planning/Gf. A four-factorial structure combining subtests from Planning/Gf and Simultaneous/Gv to form a common factor emerged as a better representation of the data. Story Completion showed a secondary loading on Knowledge/Gc. On average, most subtest variance was accounted for by the general factor. Models with bonus points for fast responses generally fitted worse than those without. Clinicians should be aware that Planning/Gf and Simultaneous/Gv measure both visual and fluid abilities. Scales of the KABC-II should not be interpreted as dimensions independent of the general factor.