Chapter One
OVERVIEW

In 1905 Alfred Binet published the first edition of what would become, about 100 years later, the Stanford-Binet V (Roid, 2003). Fifteen years after the first Binet scale, Yoakum and Yerkes published the Army Mental Tests (1920), on which the Wechsler Intelligence scales (originally published in 1939) were largely based. These measures of IQ all contained test questions that have verbal, quantitative, and nonverbal (spatial) content. The view that an intelligence test should include measures that require knowledge of vocabulary and quantitative concepts has been the basis of both group as well as individually administered IQ tests for a century (Naglieri, 2015).

IQ tests took an important evoluationary step when Alan and Nadeen Kaufman published the K-ABC in 1983. Their approach was revolutionary: take verbal and quantitative measures out of the measurment of ability and use a conceptualization of intelligence to guide the inclusion of subtests. A second evolutionary step in the advancement of intelligence and its measurement was provided in 1997 when Naglieri and Das published the Cognitive Assessment System (CAS). That approach was simlar to the one taken by the Kaufmans in so far as subtests requiring knowledge of vocabulary and arithmetic were excluded. The CAS was unique in that it contained four scales following Luria's (1973) view of four brain-based abilities. The goal was to provide a new way of defining ability based on a cognitive and neuropsychological theory and develop a test to measure these basic psychological processing abilities. The K-ABC and the CAS departed from the traditional approach to IQ because of content differences and their strong conceptual basis.

There has been an evolution in thinking about what a test of ability should be. First, there are traditional IQ tests in which verbal and quantiative test questions are an intergral part of the scales. In these instruments, vocabulary, block building, and arithmetic are considered fundamental and important ways to measure ability. More recently these tests have been partitioned in more subscales based on combining subtests into new categories conceptualized from a varieity of models. For example, although Wechsler originally had Verbal and Performance IQ scales, now the Wechsler Intelligence Scale for Children, Fifth Edition (Wechsler, 2014), has scales labeled Verbal Comprehension, Visual Spatial, Fluid Reasoning, Working Memory, and Processing Speed (see Naglieri, 2016a, for a review of the WISC-V). The content of the test, however, remains remarkably the same as what was in the Wechsler-Bellevue 1939 edition.

DON'T FORGET 1.1

Psychology advanced considerably during the 20th century, especially in the knowledge of specific abilities and the essential cognitive processes that make up intelligence. Our tests of ability should reflect that evolution.

Rapid Reference 1.1

Stanford-Binet Scales

There is a stark contrast between traditional IQ tests and the CAS (Naglieri & Das, 1997) and CAS2 as well as the K-ABC (Kaufman & Kaufman, 1983) and K-ABC-II. The essential difference between CAS (and CAS2) and traditional IQ tests relies on two main points. First, PASS (Planning, Attention, Simultaneous, and Successive) theory (see following discussion) was used to build the test and, second, CAS2 (similar to the CAS) does not have test questions that are better described as knowledge (i.e., information, similarities, vocabulary, comprehension, arithmetic) (see Naglieri & Bornstein, 2003). For these two reasons, CAS2 is not the same as a traditional IQ tests exemplified by the Binet and Wechsler scales. This raises the question: "Why use the CAS and CAS2?"

Rapid Reference 1.2

Wechsler Scales

One of the most important services professionals in this field provide is a thorough assessment of a person's abilities to answer important questions such as, "Why is the student having trouble learning?" and "How can instruction be modified to improve the student's learning?" IQ tests have been used with varying degrees of effectiveness to determine, for example,?if a learning disability exists and to explain poor performance in school. Researchers have found that traditional IQ tests have three main weaknesses. First, because the content of the verbal and quantitative questions is so similar to academic skills taught in the classroom, these tests unfairly penalize students or adults with limited educational opportunity, especially to acquire the English language (Naglieri, 2008a). Second, IQ tests have been shown to be insensitive to the cognitive problems experienced by those with, for example, specific learning disability (SLD), traumatic brain injury (TBI), and attention-deficit/hyperactivity disorder (ADHD) (Naglieri & Goldstein, 2009). Finally, attempts to use the information from IQ tests to design academic instruction have been disappointing. These limitations of traditional IQ tests provided the impetus to consider an alternative view of intelligence, which led us to the PASS theory as measured by CAS2.

DON'T FORGET 1.2

The test you select has a profound impact on what you learn about a student and what you can do to help that student.

When Naglieri and Das (1997) published the first edition of the CAS, they stated clearly that this test was based on one theory of ability. This was the first time a test of ability was built on a specific theory. That theory was chosen because of its relationship to neuropsychology as described by A. R. Luria (1973) (see Naglieri & Otero, 2011). The genius of Luria has been widely recognized and demonstrated by the considerable volume of his writings and the application of his ideas in numerous settings and places around the world.

In his book The Working Brain: An Introduction to Neuropsychology (1973), Luria described four neurocognitive processing abilities associated with three functional units of the brain. The first ability is Planning, which is a mental activity that provides cognitive control; use of processes, knowledge, and skills; intentionality; organization; and self-monitoring and self-regulation. This processing ability is closely aligned with frontal lobe functioning (third functional unit). Attention is the ability to demonstrate focused, selective, sustained, and effortful activity over time and resist distraction associated with the brain stem and other subcortical aspects (first functional unit). Simultaneous processing ability provides a person with the ability to integrate stimuli into interrelated groups or a whole usually found (but not limited to) on tasks with strong visual-spatial demands. Successive processing ability involves working with stimuli in a specific serial order, including the perception of stimuli in sequence and the linear execution of sounds and movements. It is clear from this brief explanation that PASS is very different from traditional IQ assessment, which is why researchers have found it to be more effective.

Since the publication of the first edition of the CAS there has been considerable research on the theory and the test. Naglieri (2012) and Naglieri and Otero (2011) suggested that the PASS theory has a very strong research foundation that continues to grow. For example, researchers have?shown the following:

• Individuals with distinct...