Norming tests of basic reading skills

Abstract

In developing the concepts of phonological and lexical subtypes of dyslexia, criteria have been proposed based on the projection of linear regression for raw test scores. Substantial discrepancies in subtype prevalence may arise from nonlinearities in the test scores. A norming process developed for a new nonword test, the Martin and Pratt Nonword Reading Test (Martin & Pratt, 2000), was applied to the Word Identification subtest of the Woodcock Reading Mastery Test (Woodcock, 1987) and the Regular and Irregular Word Tests published in Coltheart and Leahy (1996). These tests were administered to a representative sample of 863 children aged 6 to 15 years in the Southern Tasmanian State School population. An inverse normal transform results in a distribution which is approximately normal within age groups. On this scale the age effect was well approximated by a linear increase with the logarithm of (age - 5 years). This process can be adapted to provide norms for word lists more economically and allows convenient spreadsheet formulae for norms. Substantial differences from other norms may be attributed to school district family income differences found in this sample. Male means are lower than female for all tests, but this reflects comparable high performance and disproportionate poor performance by males on reading tests.