Wechsler Intelligence Scales

Wechsler Intelligence ScalesThe Wechsler Intelligence Scales consist of the Wechsler Preschool and Primary Scale of Intelligence (WPPSI), the Wechsler Intelligence Scale for Children (WISC), and the Wechsler Adult Intelligence Scale (WAIS). These are the most widely taught, used, and researched contemporary measures of human intelligence. Each Wechsler test consists of extensive interaction between a test taker and an administrator who assesses various cognitive abilities through a diverse array of standardized exercises. Because adult intelligence is of greatest direct relevance to career development, and because all three Wechsler scales possess a similar overall structure, the present discussion is limited to the WAIS. Research concerning the adult scale—currently in its third edition (WAIS-III)— supports its value as an indicator of intellectual ability and potential. However, decisions concerning the use of the WAIS in career assessment will depend on situational needs and constraints.

The WAIS-III conceptualizes intelligence as a general capacity for effective reasoning and behavior. This capacity is measured by performance on 11 to 14 subtests administered by a trained proctor, who adheres to a highly structured testing protocol. These tests vary considerably: some are timed, others not; some are strictly oral, others involve visual stimuli; and still others require physical manipulation of objects. The WAIS measures a person’s general intelligence level, along with more specific capacities, such as verbal and performance ability. Verbal intelligence involves verbal memory, general fund of factual knowledge, and capacity to reason with words, numbers, and other abstract symbols. Performance intelligence is visual-spatial-motor ability, including the capacity to process, integrate, manipulate, and discriminate among objects and visual stimuli (i.e., shapes, patterns, and pictures). Various WAIS subtests also measure other specific mental abilities, such as working memory and processing speed.

Because of the WAIS’s long history and widespread contemporary use in psychological assessment, scholars have produced a substantial body of supporting research. Evidence from these studies indicates that (a) there is such a thing as general intelligence, (b) intelligence is an effective if imperfect predictor of academic and job performance, and (c) the WAIS-III is a reliable and valid measure of this mental property. WAIS research has also supported its value in the assessment of specific cognitive problems, such as memory loss, attention disorders, and cognitive developmental disabilities. Particularly in career-development-related cases where such cognitive disorders are suspected, the WAIS-III is of great potential use.

Nevertheless, despite the WAIS’s obvious rigor and validity, some scholars question the sensibility of using it in career assessment of nonclinical populations. Past grades, standardized achievement test scores (e.g., the ACT), and related information can often be used in career guidance to make reasonable predictions about one’s capability of acquiring job-related skills. Similarly, in employment selection, grades and demonstrated job-related skills may be a fair indicator of potential. To the extent that these alternative sources of information are available, the added benefit of a formal intelligence score may not justify the cost and effort of administering the WAIS. Moreover, when a formal measure of general intelligence is desired, there are other available research-based assessments that are sufficiently valid and significantly more cost and time efficient.

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References:

  1. Gottfredson, L. S. 2003. “The Challenge and Promise of Cognitive  Career Assessment.”  Journal  of Career Assessment 11:115-135.
  2. Gregory, R. J. 1999. Foundations of Intellectual Assessment: The WAIS-III and Other Tests in Clinical Practice. Needham Heights, MA: Allyn & Bacon.
  3. Kaufman, A. S. and Lichtenberger, E. O. 1999. Essentials of WAIS-III Assessment. New York: John Wiley & Sons.