Specialists' Use of Tests and Clinical Judgment in the Diagnosis of Learning Disabilities

Abstract

The purposes of this study were to determine (a) which tests are most frequently used in the identification of learning disabilities, (b) how knowledgeable specialists are about the technical properties of the tests, (c) how knowledgeable professionals are about interpreting discrepancy scores, and (d) what practices are used to safeguard valid diagnoses when psychometrically inadequate tests are used clinically. A representative sample of learning disabilities teachers (n = 542), school psychologists (n = 130), and speech/language teachers (n = 179) in Colorado was selected and surveyed by questionnaire. Although subjects generally preferred tests with higher reliability and validity, poor tests were still used frequently even when superior substitutes were available. All groups of specialists tended to overrate the tests they used, and generally indicated a lack of familiarity with the psychometric properties of commonly used tests. Although a majority of specialists valued clinical judgment over test scores for diagnosis, substantial numbers appeared to lack knowledge of procedures to ensure the validity of such judgments. One-third to one-half of each specialist group could not correctly interpret ability-achievement score discrepancies.