What does the cognitive assessment system (CAS) measure? Joint confirmatory factor analysis of the CAS and the Woodcock-Johnson tests of cognitive ability (3rd edition)

Results of recent research by Kranzler and Keith (1999) raised important qu estions concerning the construct validity of the Cognitive Assessment Syste m (CAS; Naglieri & Das, 1997), a new test of intelligence based on the plan ning, attention, simultaneous, and sequential (PASS) processes theory of hu man cognition. Their results indicated that the CAS lacks structural fideli ty, leading them to hypothesize that the CAS Scales are better understood f rom the perspective of Cattell-Horn-Carroll (CHC) theory as measures of psy chometric g, processing speed, short-term memory span. and fluid intelligen ce/broad visualization. To further examine the constructs measured by the C ,AS, this study reports the results of the first joint confirmatory factor analysis (CFA) of the CAS and a test of intelligence designed to measure th e broad cognitive abilities of CHC theory-the Woodcock-Johnson Tests of Cog nitive Abilities-3rd Edition (WJ III; Woodcock, McGrew, & Mather, 2001). In this study, 155 general education students between 8 and 11 years of age ( M = 9.81) were administered the CAS and the WJ III. A series of joint CFA m odels was examined from both the PASS and the CHC theoretical perspectives to determine the nature of the constructs measured by the GAS. Results of t hese analyses do not support the construct validity of the CAS as a measure of the PASS processes. These results, therefore, question the utility of t he CAS in practical settings for differential diagnosis and intervention pl anning. Moreover, results of this study and other independent investigation s of the factor structure of preliminary batteries of PASS tasks and the CA S challenge the viability of the PASS model as a theory of individual diffe rences in intelligence.