History of Wechsler-Bellevue Intelligence Scale

The WISC is the first published intelligence test by Wechsler. A revised edition (WISC-R) in 1974 as the WISC-R, and the third edition, the WISC-III in 1991. The current version, the WISC-IV, was produced in 2003. Each successive version has renormed the test to compensate for the Flynn effect, refined questions to make them less biased against minorities and females, and updated materials to make them more useful in the administration of the test.