2 - The Wechsler intelligence scales

Summary

The Wechsler intelligence scales are individually administered, composite batteries which measure a wide range of intellectual abilities. Given the diversity of abilities measured, they are often perceived as being well suited for the assessment of learning disabilities. Accordingly, they have become some of the most extensively used and time-honored tools in learning disabilities assessment. In order to evaluate their relevance for this task, it is essential both to provide a complete description of the instruments and, more importantly, to outline clearly Wechsler scale strategies for learning disabilities assessment.

History, development, and goals

During the 1930s, David Wechsler wanted to devise a broad-band intelligence test for adults. He was in part guided by his conception that intelligence is both global in nature and also guided by a wide number of aspects of personality. Specifically, he considered that intelligence involved a person's ability to act purposively, think rationally, and deal effectively with his or her environment. Wechsler also stressed that intellectual assessment must be considered in relation to the person as a whole. This might include nonintellectual aspects of a person's functioning, such as interests, persistence, drive, or need for achievement. Despite this early emphasis on a general or unitary aspect of intelligence, there has been considerable interest and controversy concerning the extent to which the Wechsler scales can measure more specific aspects of a person's functioning (Lezak, 1988; McDermott, Fantuzzo, & Glutting, 1990; Kaufman, 1994; Glutting et al., 1997).