WAIS-IV Wechsler Adult Intelligence Scale - Fourth Edition (WAIS-IV)

The Wechsler Adult Intelligence Scale - Fourth Edition (WAIS-IV, Pearson Assessments, 2012) was designed to evaluate cognitive functioning in adults aged 16 to 90. The WAIS-IV is the most recent updated version (released in 2008) of the most commonly administered intelligence test for adolescents and adults (Canivez, 2010). The test has its roots in the Wechsler -- Bellevue Intelligence Scale (Wechsler, 1939). David Wechsler, a psychologist who was dissatisfied with the standard of intelligence testing of the times, based his original tests on his notion of intelligence as "the global capacity of an individual to act purposefully, think rationally, and deal effectively with the environment" (Wechsler, 1939, p. 229). All versions of the WAIS attempt to measure general intelligence and other facets of intelligence via the administration of numerous subtests. Each of these subtests is an estimate of a particular cognitive ability that is an indicator of a particular facet of intelligence (Canivez, 2010).

The WAIS-IV has six major IQ indices that include a Verbal Comprehension Index (a measure of verbally-mediated intelligence), Perceptual Reasoning Index (a measure of non- -- verbally -- mediated intelligence), a Processing Speed Index (a measure of how quickly a person can complete automatic tasks), a Full Scale Index (and overall IQ score), and a General Ability Index (an optional index that provides an estimate of general IQ without the contribution of working memory and processing speed; Whiston, 2012). These general indices are calculated from the scores of 10-15 subtests that contribute to the overall score on the particular ability (Canivez, 2010).

The tests require specific expertise to administer. For instance Pearson Assessments, the manufacturer of the WAIS-IV, will only allow individuals with doctorate degrees in psychology, education or related...

Specialized training in administering the test is required by organizations such as the American Psychological Association, etc. (Pearson Assessments, 2012).
The administration of the basic subtests is lengthy (from 60 -- 90 minutes) and the scoring procedures and interpretation are quite complex (Whiston, 2012). Specially trained technicians can administer the test (these technicians must have at least a bachelors degree in a related field); however, tests interpretation requires an advanced degree in a field such as psychology, education, or related field (Pearson Assessments, 2012; Whiston, 2012). This interpretation includes understanding the specific subtest scores, Index scores, and how they are derived as well as noting observations of the client as they work their way through the tests during the assessment. Some of the subtests require special apparatus to complete (e.g., Block Design test), whereas others are simply question-and-answer. The administration of the test is completed through standardized procedure such that everyone who receives the test is tested in nearly the exact same manner, thus increasing the reliability and validity of the test results (Whiston, 2012). The standardized procedure includes defining the types of assistance the administrator can provide and the types of questions that can be answered or asked by the administrator to enhance the performance of individual. The test items are scored via instructions in the manual that the administrator must use during every administration and are then standardized based on normative data that has been collected by the test producer (Canivez, 2010). The standardized scores allow for the comparison of individual efforts across a large domain of demographic variables. The test manual has information regarding the standardization sample and great efforts are made to make…