Modern Tests
Well-known modern IQ tests include Raven's Progressive Matrices, Wechsler Adult Intelligence Scale, Wechsler Intelligence Scale for Children, Stanford-Binet, Woodcock-Johnson Tests of Cognitive Abilities, and Kaufman Assessment Battery for Children.
Approximately 95% of the population have scores within two standard deviations (SD) of the mean. If one SD is 15 points, as is common in almost all modern tests, then 95% of the population are within a range of 70 to 130, and 98% are below 131. Alternatively, two-thirds of the population have IQ scores within one SD of the mean, i.e. within the range 85-115.
IQ scales are ordinally scaled. While one standard deviation is 15 points, and two SDs are 30 points, and so on, this does not imply that mental ability is linearly related to IQ, such that IQ 50 means half the cognitive ability of IQ 100. In particular, IQ points are not percentage points.
The correlation between IQ test results and achievement test results is about 0.7.
Read more about this topic: Intelligence Quotient
Famous quotes containing the words modern and/or tests:
“The real accomplishment of modern science and technology consists in taking ordinary men, informing them narrowly and deeply and then, through appropriate organization, arranging to have their knowledge combined with that of other specialized but equally ordinary men. This dispenses with the need for genius. The resulting performance, though less inspiring, is far more predictable.”
—John Kenneth Galbraith (b. 1908)
“Although she feeds me bread of bitterness,
And sinks into my throat her tiger’s tooth,
Stealing my breath of life, I will confess
I love this cultured hell that tests my youth!”
—Claude McKay (1889–1948)