Wechsler Adult Intelligence Scale
The original WAIS (Form I) was published in February 1955 by David Wechsler, Chief Psychologist at Bellevue Hospital (1932–1967) in NYC, as a revision of the Wechsler–Bellevue Intelligence Scale released in 1939.
[3][4] The WAIS was founded to get to know Wechsler's patients at Bellevue Hospital and on his definition of intelligence, which he defined as "... the global capacity of a person to act purposefully, to think rationally, and to deal effectively with his environment.
His argument, in other words, is that general intelligence is composed of various specific and interrelated functions or elements that can be individually measured.
However, the present-day WAIS-IV has contradicted many of these criticisms, by incorporating a single overall score, using multiple timed tasks, focusing on intellective items and other ways.
In turn, this allowed for an analysis to be made of an individual's ability in a variety of content areas (as opposed to one general score).
This scale required a subject to actively do something, such as copying symbols or pointing to a missing detail in a picture, rather than just answering questions.
Clinicians were able to observe how a participant reacted to the "longer interval of sustained effort, concentration, and attention" that the performance tasks required.
[6] The WAIS was initially created as a revision of the Wechsler–Bellevue Intelligence Scale (WBIS), which was a battery of tests published by Wechsler in 1939.
Because the Wechsler tests included non-verbal items (known as performance scales) as well as verbal items for all test-takers, and because the 1960 form of Lewis Terman's Stanford–Binet Intelligence Scales was less carefully developed than previous versions, Form I of the WAIS surpassed the Stanford–Binet tests in popularity by the 1960s.
Some new contributors to the third edition of the most commonly used test of intellectual abilities include Hsin‐Yi Chen, Louise O’Donnell, Mark Ledbetter, David Tulsky, and Jianjun Zhu.
The GAI is clinically useful because it can be used as a measure of cognitive abilities that are less vulnerable to impairments of processing speed and working memory.
[12] The demographic characteristics of the sample were modeled after the proportions of different groups in an analysis of data from the U.S. Census Bureau.
The Full Scale Intelligence Quotient is now generated from only seven subtests (Similarities, Vocabulary, Block Design, Matrix Reasoning, Figure Weights, Digit Span Sequencing, Coding), similar to the WISC-V. Fifteen ancillary index scores, including the General Ability Index, are also present.
[14] Intelligence tests may be used to assess the level of cognitive functioning in individuals with psychiatric illness or brain injury.
Rehabilitation psychologists and neuropsychologists use neuropsychological tests (including the WAIS-IV) to assess how the individual's brain is functioning after it has been injured.
[15][16][17] The Wechsler Abbreviated Scale of Intelligence – 2nd edition (WASI-II) is a short psychological test that was developed in 2011 by Pearson to estimate intellectual functioning in a shorter period of time than the WAIS-IV.
