A Comparison of the SB5 and the CAS in Educational Psychology Practice

Two tests of intellectual ability were compared in terms of quantitative measures and professional utility in the context of 41 students who were referred for psychoeducational investigation of their learning. Full-scale, Composite, and Factor scores from The Stanford Binet Intelligence Scales — Fifth Edition (SB5) and the Das Naglieri Cognitive Assessment System (CAS) were compared and individual profiles were examined. The SB5 is the latest version of a traditional test referenced to the Cattell-Horn-Carroll factor model of intelligence, while the CAS was developed from an information processing theory of intelligence. Full-scale measures of intellectual ability were found to differ significantly, with the SB5 approximately 8 points higher than the CAS. Analysis of the profiles assisted in understanding specific learning abilities and guided interventions. The implications of this for the relative utility of the two instruments, their interchangeablity, the meaningful interpretation of results, and their complementary contribution to practice are discussed.