Long-Term Stability of Intelligence and Achievement Scores in Specific-Learning-Disabilities Samples

Abstract

To compile data useful for informed reevaluation decisions that concern specific-learning-disabled (SLD) children, the stability of the Wechsler Intelligence Scale for Children-Revised (WISC-R) and Wide Range Achievement Test (WRAT) scores was assessed over a period of approximately 3 years in two samples of SLD children. Both samples began in a part-time learning-disabilities program (SLD-P). At the second WISC-R testing, 68 students remained in the part-time program, and 31 students had been placed in a full-time SLD program (SLD-PF). The WISC-R IQ reliabilities were high with the exception of Verbal IQ(VIQ) in the SLD-PF group. WRAT scores were less reliable. For both groups, VIQs decreased and Performance IQs (PIQs) increased over time. In the SLD-P group WRAT-Math scores decreased over time, and in the SLD-PF group WRAT-Spelling scores decreased over time. Regression analyses that used time in program as a covariate revealed unimpressive effects of program on WISC-R and WRAT scores. Cautions about program placement and the experimental design are discussed.