Curriculum bias in standardized tests of reading decoding

This study examined overlap between four basal reading programs and the phonetic analysis subtest of three standardized achievement measures. Raw scores, percentages of items correct, grade equivalents, and percentile scores were computed for a hypothetical student who had mastered all grapheme-phoneme correspondences taught at each grade level. The results indicated that (a) programs differed in the number and sequence of phonics skills taught; (b) percentile and grade-equivalent scores differed across programs at each grade level for a given test; and (c) the proportion of grade-equivalent scores falling at or above expected grade levels differed across tests for a given program (range of 29%-71%). The implications for selecting and interpreting standardized measures of reading decoding are discussed.