An earlier study (D. Koretz, 1997) found that Kentucky had been unusually successful in testing most students with disabilities, but it also found numerous signs of poor measurement, including differential item functioning (DIF) in mathematics, apparently excessive use of accommodations, and implausibly high mean scores for some groups of students…

The tetrad of subtests of the Wechsler Intelligence Scale for Children-Revised (WISC-R) that best predicts the WISC-R Full-Scale intelligence quotient (IQ) was determined for 1,589 Appalachian students referred for evaluation in grades 1-4, 5-8, and 9-10. The sample was divided into three groups. Students in grades 1 through 4 (n=655) were those…