Intelligence Testing and the Field of Learning Disabilities: A Historical and Critical Perspective

Abstract

One of the most significant characteristics of the development of American education during the past seven decades is the remarkable growth in utilization of intelligence tests. As fundamental component of efforts to make educational research more scientific and educational practice more efficient, intelligence testing has gained an important and apparently secure position in American education. Intelligence tests are used in variety of ways. In the field of learning disabilities, for example, intelligence scores are used extensively to identify children for learning disability services. According to recent state and federal regulations, child is considered learning disabled if he/she demonstrates a severe discrepancy between achievement and intellectual in any of several intellectual areas (Sec. 121a.541 of Amended PL 94-142). Professionals in learning disabilities (LD) have developed several formulas for determining such discrepancies--all of them relying on intelligence scores as the indicator of intellectual ability (O'Donnell, 1980). Recent information provided by the California State Department of Education (CSDE) (1983a) concerning LD eligibility also illustrates the importance placed on standardized intelligence scores when identifying child as learning disabled: The determination of severe discrepancy necessitates the use of standardized achievement test and test of intellectual ability. The required 1.5 standard deviation criteria is the that must be corroborated by other assessment data. (CSDE No. 1, p. 1) A number of other states have adopted IQ scores as the critical threshold for determining LD eligibility. In fact, intelligence testing has become so common that its utility or efficacy is rarely questioned. Such wide acceptance of intelligence testing should not imply, however, that intelligence tests have achieved satisfactory level of design or implementation. From the beginning, intelligence testing has encountered serious theoretical and practical problems which have cast doubt over the tests' ability to yield proper and accurate information. This article contains review of the