What's Your IQ

Three functional units, four processes

The PASS theory rests on the Russian neuropsychologist A. R. Luria's account of three functional units of the brain, which work together in any mental activity.^4,1 Das, Naglieri and Kirby set out the theory in 1994, and the CAS put it into practice in 1997.⁵

Unit 1Regulates cortical arousal and attention.⁴

Attention

Unit 2Codes information using simultaneous and successive processes.⁴

SimultaneousSuccessive

Unit 3Develops and uses strategies, and monitors and controls thinking. Located in the frontal lobes.⁴

Planning

The effort to offer an alternative to the IQ test goes back to work by Das, Kirby and Jarman in 1975 and 1979.⁷ The CAS's Planning scale is described as very similar to executive function.⁵

EXPLORE · A PUBLISHED CASE, THEN YOUR OWN

Which process matches the reading problem?

A published example describes a child referred for reading problems, with a reading-decoding score of 80. Their PASS scores were 110, 106 and 94, except Successive at 81, the score that matched the reading difficulty.⁴ Load it, or move the sliders.

Planning110Attention106Simultaneous94Successive81Reading score80

PASS mean 98

Reading 80

110

106

PlanningAttentionSimultaneousSuccessive

Successive is low relative to the other processes and in line with the reading score. That's the pattern the published case uses to connect a process weakness to the reading difficulty.

Illustrative: bars at least 10 points below the child's own PASS average are highlighted, and "matches" means within 5 points of the reading score. These cut-offs aren't the CAS's official rules. Scores use a mean of 100 and SD of 15.²

Twelve subtests, three for each process

Solid = the 8-subtest Core Battery (2 per process); faded = extra subtests in the 12-subtest Extended Battery^5,2

Reliability by scale

Core (8 subtests)

.84–.93

Extended (12)

.90–.94

The lowest figure is for Attention and the highest for Simultaneous, in both batteries.²

Questioned, then revised

1994

The PASS theoryDas, Naglieri and Kirby describe the theory the test is built on.⁵

1997

CAS publishedTwelve measures, three for each PASS process, with scales matching Luria's view of neurocognitive abilities.⁵

1999

Construct validity questionedResearch by Kranzler and Keith raised important questions about whether the CAS measures the four processes it claims to.⁸

2014

CAS2Naglieri, Das and Goldstein publish the second edition, with a suite of versions including a brief form. It reports a Full Scale score and the four PASS scales.²

2015

A largely positive reviewA review found the materials of exceptional quality and the test relatively easy to learn, once users are used to its focus on strategy in the Planning tests.⁶

Age ranges differ between sources: 5–17 for the CAS, and 4 or 5 to 18:11 for the CAS2.^7,9

References

[1]Cognitive Assessment System (CAS): psychometric studies. Universidade de Évora repository (PDF).dspace.uevora.pt

[2]Naglieri, J. A., & Otero, T. M. The Cognitive Assessment System: from theory to practice (CAS2 chapter). ResearchGate.researchgate.net

[3]Wikipedia contributors. PASS theory of intelligence (accessed 30 Sept 2026).en.wikipedia.org

[4]The Das–Naglieri Cognitive Assessment System: suitable for inclusion? ResearchGate.researchgate.net

[5]The Das-Naglieri Cognitive Assessment System in theory and practice. ResearchGate.researchgate.net

[6]Test review: Naglieri, Das & Goldstein (2014), Cognitive Assessment System–Second Edition. Journal of Psychoeducational Assessment (2015). ERIC EJ1063651.eric.ed.gov

[7]Wikipedia contributors. Das–Naglieri Cognitive Assessment System (accessed 30 Sept 2026).en.wikipedia.org

[8]Cognitive Assessment System (CAS): a review. ResearchGate.researchgate.net

[9]Cognitive Assessment System – Second Edition. Texas Statewide Leadership for Autism Training.txautism.net

HOW TO CITE THIS PAGE

What's Your IQ. (2026). Das-Naglieri Cognitive Assessment System (1997). In Historical IQ Tests Archive. Retrieved September 30, 2026, from /en/historical-iq-tests/das-naglieri-cas-1997

EDITORIAL RECORD

First published2026

Last reviewed30 September 2026

Sources9, all from visible search results

Open questionsCAS2 lower age (4 vs 5); names of the 12 subtests; 1997 norm sample

Canonical URLwhats-your-iq.com/en/historical-iq-tests/das-naglieri-cas-1997

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Luria, first1983

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Naglieri's matrix test for gifted screening. Both reflect his interest in assessing ability without leaning on verbal knowledge.

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Attention on its own1962

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A cancellation test of sustained attention. The CAS treats attention as one of four processes within a full battery.

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Planning, early1915

Porteus Maze Test

Porteus's mazes were an early attempt to test planning ahead. The CAS gives planning its own scale.

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The traditional scales1974

WISC-R

The WISC-R's verbal and performance scales are exactly the kind of traditional structure the CAS set out to replace with processes.

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A different theory1977

Woodcock-Johnson

The Woodcock-Johnson built on Gf-Gc and then CHC theory, a psychometric route. The CAS took a neuropsychological route instead.

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Part of the Historical IQ Tests Archive. Editorial content under CC BY-SA 4.0. CAS and CAS2 are registered marks of their publisher; no test items are reproduced.

BibTeX RIS

Intelligence as four brain processes.

Three functional units, four processes

Which process matches the reading problem?

Twelve subtests, three for each process

Questioned, then revised

References

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Your own profile, in four domains.