Wechsler Intelligence Scale

The Wechsler Intelligence Scale for Children and Adults
The Wechsler Intelligence Scale is an intelligence test that can be administered to both children and adults. Developed by Dr. David Wechsler, a clinical psychologist with Bellevue Hospital, in 1939, the tests measure one's ability to "adapt and constructively solve problems in the environment," as Wechsler defined.

The Wechsler Intelligence Scale for Children
The Wechsler Intelligence Scale for Children is an individually administered test for children between the ages of 6 and 16. It can be completed without any reading or writing, and takes 65 to 80 minutes to complete. It generates an IQ score, which represents a child's cognitive ability.
The test is divided into 15 subtests, 10 of which are from previous versions of the test. Supplemental subtests are used to accommodate children in rare cases or to make up for spoiled results due to interruptions or other causes.

The WISC contains several of the subtests of the Wechsler Intelligence Scale and has been revised five times into the fall 2014 version, the WISC-V.

The Wechsler Intelligence Scale for Adults
Designed to measure intelligence in adults and older adolescents, the WISA is in its fourth version which was published by Pearson in 2008. The test contains 10 subtests and 5 supplemental tests. The core tests comprise the entire IQ scale, and determines the capacity of a person to act and think purposefully and rationally and to deal effectively with his environment. It takes around 90 minutes to complete.
The WAIS is appropriate for adults and adolescents ranging from 16 to 90 years of age.

Scoring and Administration
Each test is comprised of two groups of subtests: Verbal and Performance. Verbal scales measure general knowledge, language, reasoning, and memory skills. Performance measures spatial, sequencing, and problem-solving skills.
Each test is individually administered by a trained examiner and requires a complex set of test materials. The Full Scale IQ score is determined by a formula that sums the Verbal and Performance IQ scores. A score beyond 130 is considered superior or "gifted", 120-129 is "very high", 110-119 are considered "bright normal", and anything less than 90 is considered average to low average. Anything lower than a 70 signals borderline mental functionality, and any lower than 69 signals mental retardation.