Precision of age norms in tests used to assess preschool children

Abstract

This study investigated normative precision in 14 preschool tests representing four domains: cognitive, language, adaptive behavior, and early academic skills. The purpose was to explore the consequences of using tests with more- vs. less-precise age norms to identify disabilities in preschool children. As expected, on tests with more precise norms, standard scores associated with the same raw score shifted gradually across age groups. On the other hand, tests with less precise norms showed more dramatic standard score shifts across age groups. Examination of the degree of shift found in each test indicated that many preschool tests have norm tables that are potentially problematic for diagnosing disabilities, particularly for children near norm group cut-off ages. On high stakes tests, an optimal span is one to three months. This standard can be achieved by using interpolation and/or increasing the size of norming samples at the preschool level. © 1999 John Wiley & Sons, Inc.