David Wechsler (January 12, 1896, Lespedi, Romania - May 2, 1981, New York, New York) was a leading Romanian-American psychologist. He developed three well-known intelligence scales, namely the Wechsler Adult Intelligence Scale (WAIS) and the Wechsler Intelligence Scale for Children (WISC). January 12 is the 12th day of the year in the Gregorian calendar. ... 1896 (MDCCCXCVI) was a leap year starting on Wednesday (see link for calendar). ... May 2 is the 122nd day of the year in the Gregorian calendar (123rd in leap years). ... 1981 (MCMLXXXI) was a common year starting on Thursday of the Gregorian calendar. ... Midtown Manhattan, looking north from the Empire State Building, 2005 New York City (officially named the City of New York) is the most populous city in the state of New York and the entire United States. ... A Romanian-American is a citizen of the United States who has significant Romanian heritage. ... A psychologist is a scientist who studies psychology, the systematic investigation of the human behavior and mental processes. ... Wechsler Adult Intelligence Scale or WAIS is a general test of intelligence (IQ), published in February 1955 as a revision of the Wechsler-Bellevue test (1939), standardised for use with adults over the age of 16. ... To meet Wikipedias quality standards, this article may require cleanup. ...

Biography

Wechsler was born in Romania and emigrated with his parents to the United States as a child. He studied at the City College of New York and Columbia University, where he earned his master's degree in 1917 and his Ph.D. in 1925 under the direction of Robert S. Woodworth. During World War I he worked with the United States Army to develop psychological tests to screen new draftees while studying under Charles Spearman and Karl Pearson. The City College of The City University of New York (known more commonly as City College of New York or simply City College, CCNY, or colloquially as City) is a senior college of the City University of New York, in New York City. ... Columbia University is a private university in the Morningside Heights neighborhood of Manhattan in New York City and a member of the Ivy League. ... Robert Sessions Woodworth (1869-1962) was an influential American academic psychologist of the first half of the twentieth century. ... Combatants Allies: Serbia, Russia, France, Romania, Belgium, British Empire, United States, Italy, and others Central Powers: Germany, Austria-Hungary, Bulgaria, Ottoman Empire Casualties Military dead: 5 million Civilian deaths: 3 million Total of dead: 8 million Military dead: 4 million Civilian deaths: 3 million Total dead: 7 million The First... To meet Wikipedias quality standards, this article or section may require cleanup. ... Charles Edward Spearman (September 10, 1863 - September 7, 1945) was an English psychologist known for work in statistics, as a pioneer of factor analysis, and for Spearmans rank correlation coefficient. ... Karl Pearson (pencil sketch in notebook; there is some see-through of writing on next page) Karl Pearson (March 27, 1857 – April 27, 1936) was a major contributor to the early development of statistics as a serious scientific discipline in its own right. ...

After short stints at various locations (including five years in private practice), Wechsler became chief psychologist at Bellevue Psychiatric Hospital in 1932, where he stayed until 1967. He died in 1981, his psychological tests already being highly respected. This article needs to be cleaned up to conform to a higher standard of quality. ... 1932 (MCMXXXII) was a leap year starting on Friday (the link will take you to a full 1932 calendar). ... 1967 (MCMLXVII) was a common year starting on Sunday of the Gregorian calendar (the link is to a full 1967 calendar). ... 1981 (MCMLXXXI) was a common year starting on Thursday of the Gregorian calendar. ...

Intelligence scales

Wechsler is best known for his intelligence tests. The Wechsler Adult Intelligence Scale (WAIS) was developed first in 1939 and then called the Wechsler-Bellevue Intelligence Test. From these he derived the Wechsler Intelligence Scale for Children (WISC) in 1949 and the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) in 1967. Wechsler originally created these tests to find out more about his patients at the Bellevue clinic and he found the then-current Binet IQ test unsatisfactory. The tests are still based on his philosophy that intelligence is "the global capacity to act purposefully, to think rationally, and to deal effectively with [one's] environment" (cited in Kaplan & Saccuzzo, p. 256). 1939 (MCMXXXIX) was a common year starting on Sunday (link will take you to calendar). ... 1949 (MCMXLIX) was a common year starting on Saturday (the link is to a full 1949 calendar). ... 1967 (MCMLXVII) was a common year starting on Sunday of the Gregorian calendar (the link is to a full 1967 calendar). ... The modern field of intelligence testing began with the Stanford-Binet IQ test. ...

The Wechsler scales introduced many novel concepts and breakthroughs to the intelligence testing movement. First, he did away with the quotient scores of older intelligence tests (the Q in "I.Q."). Instead, he assigned an arbitrary value of 100 to the mean intelligence and added or subtracted another 15 points for each standard deviation above or below the mean the subject was. Rejecting a concept of global intelligence (as was propagated by Charles Spearman), he divided the concept of intelligence into two main areas: verbal and performance (non-verbal) areas, each further subdivided and tested with a different subtest. These conceptualizations are still reflected in the most recent versions of the Wechsler scales. IQ tests are designed to give approximately normally distributed results, which causes a bell curve graph of IQ score frequency. ... In probability and statistics, the standard deviation is the most common measure of statistical dispersion. ... The English psychologist Charles Spearman, in his 1904 book, General Intelligence - Objectively Determined and Measured, described his two-factor theory of intelligence, using his strong background in statistics. ... Intelligence is the mental capacity to reason, plan, solve problems, think abstractly, comprehend ideas and language, and learn. ...

The WAIS is today the most commonly administered psychological test (Kaplan & Sacuzzo, 2005). The tests are currently updated approximately every ten years to compensate for the Flynn effect. The Flynn effect is the continued year-on-year rise of IQ test scores, an effect seen in most parts of the world, although at greatly varying rates. ...

Sources

Kaplan, R. M., & Saccuzzo, D. P. (2005). Psychological testing: Principles, applications, and issues. Thomson Wadsworth.