Reitan, R. (2004). Clinical and Forensic Issues Regarding Age, Education, and the Validity of Neuropsychological Test Results: A Review and Presentation of a New Study. Journal of Forensic Neuropsychology, 4(1), 1-32.
This paper reviews procedures and reports of adjustments of raw scores from the Halstead-Reitan Neuropsychological Test Battery for Adults using the method proposed by Heaton, Grant, and Matthews (HGM; 1991). Arguments and findings both supporting and criticizing the HGM transformations are reviewed. From a psychometric viewpoint, the conclusion is reached that the HGM method, which is based only on a neurologically-normal group, transforms raw scores into scaled scores that tend to fall in the normal range, especially for brain damaged persons. Although this question is not yet adequately researched, the effect may stem principally from adjustments made for persons with less education and older age. The consequent result of the adjustments, in this case, would be to produce normal scores for tests that were designed, developed, and validated as measures of brain impairment-! defeating the very purpose of the tests as neuropsychological measures. If the transformation process, based on age and education, is faulty for any reason (including inadequacies of the normative sample), and the transformations skew the raw scores either in the direction of normalcy or brain impairment, a serious problem exists in clinical interpretation or in a forensic setting. Thus, the questions raised in this paper are of theoretical, clinical, and forensic importance, and are urgently in need of resolution through further empirical research.