David Weschler's contribution to intelligence testing
David Weschler was a psychologist who was known for his intelligence tests. He belived that factors other than intelligence are involved with intelligent behavior. He had three intelligence tests, the Weschler Adult Intelligent Scale (WAIS) in 1939, the Weschler Children Intelligence Scale (WCIS) in 1949, and the Weschler Preschool and Primary Test of Intelligence (WPPSI) in 1967. Weschler's scales were different than the others at the time. One of the changes he made is everyone starts out with a score of 100, and he had to add/subtract 15 points each standard deviation above/below the average. Today, the WAIS is one of the most widely used intelligence tests.
Lewis Terman's role in the Development of Intelligence Testing
Lewis Terman is known for his revision of the Binet-Simon Scale. He named his intelligence test the "Stanford-Binet Intelligence Quotient Test". The test was made to diagnose developmental or cognitive deficiencies in children. It measures 5 factors, and is given in verbal and nonverbal segements. The five factors are as follows:
- Fluid reasoning
- Quantitative reasoning
- Visual-spatial processing
- Working memory
The Stanford-Binet Intelligence Scale is one of the first examples of an adaptive test.
The Difference Between Reliability and Validity.
Reliability and validity are two completely different things. Reliability is basically how consistent a test is. When attempting to check the reliability of a test, ask yourself "Can I take this test over and over again to get the same result?". Validity is the ability to measure what the test was designed to measure. For example, if a test was designed to measure intelligence, but instead measures how good at naming cheeses you are, it is not a valid test.