A widely used series of intelligence tests developed by clinical psychologist David Wechsler.

The Wechsler Intelligence Scales are divided into two sections: verbal and nonverbal (or "performance"), with separate scores for each. Verbal intelligence, the component most often associated with academic success, implies the ability to think in abstract terms using either

words or mathematical symbols. Performance intelligence suggests the ability to perceive relationships and fit separate parts together logically into a whole. The inclusion of the performance section in the Wechsler scales is especially helpful in assessing the cognitive ability of children with speech and language disorders or whose first language is not English. The test can be...