Wechsler Bellevue Intelligence Scale

Purpose: Designed as a general test of cognitive ability for children and adults.

Population: Ages 10 and over.

Score: Verbal, Performance, and Full Scale IQ.

Time: (40-60) minutes.

Author: David Wechsler.

Publisher: The Psychological Corporation.

Description: The Wechsler Bellevue Intelligence Scale (WBIS) is a general test of intelligence, which Wechsler defined as, "... the global capacity of the individual to act purposefully, to think rationally, and to deal effectively with his environment." In keeping with this definition of intelligence as an aggregate of mental aptitudes or abilities, the WBIS consists of 11 subtests divided into two parts, verbal and performance.

Scoring: The battery of tests consists of six Verbal and five non-verbal or Performance tests as follows: an information test, a general comprehension test, a memory span test (digits forward and backward), an arithmetical reasoning test, a similarities test, a vocabulary test, a block design test, an object assembly test and a digit symbol test.

Reliability: Reliability coefficients for the subtests range from .62 to .88. The Verbal IQ, Performance IQ, and Full Scale IQ have reliability coefficients of .84, .86, and .90, respectively.

Validity: The author investigates correlations between the WBIS and other tests of cognitive ability. The coefficients are as follows: Stanford-Binet, 1937 rev., .62; Otis, .73; Raven Progressive Matrices, .55, and the Army Alpha test, .53.

Norms: The WBIS was standardized on 1750 subjects of both sexes, ages 7-69. This sample’s demographic characteristics are not representative of the United State population.

Suggested Uses: Because of its dated normative and psychometric data, the WBIS is recommended for teaching purposes only.