The Peabody Individual Achievement Test (PIAT, Dunn & Markwardt, 1970) and the Woodcock Reading Mastery Tests (Woodcock, 1973) are two tests widely used for the purpose of: a) The diagnosis of learning disabilities. For example, in Tennessee there must be a discrepancy of more than one standard deviation between expected and actual reading level, while in Ohio the difference must be two standard deviations. b) The demonstration of gain scores to assess the efficacy of instructional strategies or teaching effectiveness.