A validity study of the Quick Neurological Screening Test-Revised for learning-disabled students.

Abstract

In the past two decades, a great deal of information has been amassed in the area of developmental neuropsychology and central processing deficiencies in children. There is evidence that brain dysfunction can play a major role in the etiology of such deficiencies. Also recognized is the direct association between brain deficits and their etiological relationship to an individual's learning problem. Current definitions of learning disabilities reflect a variety of psychological correlates of neurological dysfunction. There is a general lack of research into the precise nature of the underlying functions that may be detected by neuropsychological assessment. Presently only one brief neuropsychological screening instrument measures performance using age-corrected norms: the Quick Neurological Screening Test-Revised (QNST-R; Mutti, Sterling, Spalding, & Crawford, 1978). This study was designed to determine the construct validity of the QNST-R with a learning disabled (LD) population. Scores of 122 children, 40 females and 82 males, ages six years, four months to 13 years, five months were collected on 14 subtests from the QNST-R. Principal components factoring of the original correlation matrix disclosed a five factor solution, which accounted for 57% of the original variance. Analysis of the initial correlation matrix revealed very low loadings between the 14 subtests, suggesting that each subtest measures a disparate aspect of student performance. Only one extractible factor exhibited high enough loadings to be interpretable, which was labeled Tactile-kinesthic-motor/left-right differences. This factor accounted for 21% of the variance. Factor analysis substantiated the hypothesis that limited factorial validity does exist for the QNST-R; however, the analysis also suggested that the test lacked the capability of assessing a range of diverse and independent functions, when used with this LD population. A number of diverse independent functions which are claimed to be measured by the QNST-R, and which need to be measured in order to produce a useful neuropsychological screening instrument, do not appear to exist for the LD population. Finally, age differences were revealed which suggest that younger children have greater difficulty successfully completing the QNST-R items than do older children. The need for further study is discussed. Alternative explanations for the results of the present study are presented.