This Digest introduces the advantages and disadvantages of three commonly used methods of reporting test score changes: (1) change in percentile rank; (2) scale or raw score change; and (3) percent change. The change in percentile rank method focuses on the increase or decrease of the mean percentile ranking for a group of students. This method…

An earlier Digest described the shortcomings of three methods commonly used to summarize changes in test scores. This Digest describes two less commonly used approaches for examining changes in test scores, those of Standardized Growth Estimates and Effect Sizes. Aspects of these two approaches are combined and applied to the Iowa Test of Basic…

Difficulties inherent in differentiating practice effects from meaningful change in neuropsychological retest data are illustrated in this case study of a personal injury case. Although the patient demonstrated substantial gains on the Wechsler Adult Intelligence Scale Revised, most of the tests given on successive days did demonstrate acceptable…