Cognitive Assessment System - History

History

CAS development began with an attempt to offer an alternative to the IQ test (Das, Kirby & Jarman, 1975, 1979). Developed and published in 1997 by J.P. Das, PhD of the University of Alberta and Jack Naglieri, PhD, then at Ohio State University, the CAS has its theoretical bases both in the neuropsychology of Luria as well as in cognitive psychology.

CAS is based on the Planning, Attention-Arousal, Simultaneous and Successive (PASS) cognitive processing theory (or the PASS Theory of Intelligence), a modern theory within the information-processing framework (Das, Naglieri & Kirby, 1994). Roots of CAS are in Luria’s (1973) organization of cognitive functions in the brain as well as in cognitive psychology of Baddley, Estes, Posner and other contemporary psychologist. Their work has guided the selection and interpretation of CAS tests.

The Kaufman Assessment Battery for Children or KABC by (Alan S. Kaufman, 1983 ) is perhaps the first battery of commercially available tests to provide a psychometric assessment of cognitive processes. K-ABC has used several references to the early research of Das and his colleagues (Das, Kirby & Jarman,1979) on simultaneous and successive processing, a precursor to PASS theory. KABC did not assess the Arousal-Attention, and Planning functions, as CAS did, until K-ABC II appeared in 2004. The latter provides two theoretical bases, one of them in Luria (1966) and by default, the 4 PASS processes) and the other in Cattell-Horn-Carroll model (CHC) which is essentially an elaboration of fluid and crystallized intelligence (McGrew 2005). Some may consider this a strength of KABC-II. However, two important features of CAS have set it apart from ability measures within fluid and crystallized abilities of CHC, and verbal-performance IQ:

• CAS is a system of assessment of ‘processes’, not abilities. Ability tests such as WISC/WAIS
• those that measure fluid and crystallized abilities address different constructs than process assessments. CAS process measures may have the same contents in several of its sub-tests (i.e. verbal, as in Simultaneous Verbal, and Word-series, see next section) but the codes are different (Simultaneous contrasted with Successive. see McCrea 2009 for further discussion).