Standardized Achievement Tests: How Useful for Special Education?

The extent and direction of curriculum bias in standardized reading achievement tests are examined. Bias was estimated by comparing the relative overlap in the contents of four separate reading achievement tests with the contents of five commercial reading series at first and second grade levels. Overlap between each achievement test and each reading series is reported in terms of achievement test grade equivalent scores that would be expected given mastery of the words that appear both as content in a reading series and as achievement test items. Results indicate clear discrepancies between the grade equivalent scores obtained, both between tests for a single curriculum and on a single test for different reading curricula. The implications of the apparent curriculum bias of achievement tests are discussed as they relate to evaluation of teachers, children, and curricula; to reading placement; and to the identification and classification of exceptional children.