When classifying the evidence base of practices, special education scholars typically appraise study quality to identify and exclude from consideration in their reviews unacceptable-quality studies that are likely biased and might bias review findings if included. However, study quality appraisals used in the process of identifying evidence-based…

This article synthesizes reading intervention research studies intended for use with struggling or at-risk students to determine which studies adequately address population validity, particularly in regard to the diverse reading needs of English language learners. An extensive search of the professional literature between 2001 and 2010 yielded a…

Reviewed are the technical problems in the work of Grill and Bartel who attempted to demonstrate that a bias exists in the Grammatical Closure subtest of the Illinois Test of Psycholinguistic Abilities against speakers of nonstandard English. (SBH)

Presented are a rebuttal and a counter-rebuttal to an earlier article questioning the educational usefulness of perceptual tests with learning disabled children. (DB)

A study of 22 learning disabled (LD) and normal children (mean age nine years) was undertaken to illustrate the research problems involved in using analysis of covariance to control for differences between LD and normal children on measures of intelligence. (SW)

For successful classification of children with attention deficit-hyperactivity disorder, major issues include (1) the need for explicit studies of identification criteria; (2) the need for systematic sampling strategies; (3) development of hypothetical classifications; and (4) systematic assessment of reliability and validity of hypothetical…

Two methodological problems often arising in dyslexia research are considered. The first problem concerns the validity of experimental measures and the related problem of interpreting null results. The second problem involves the effects of sampling from a disabled population if the disorder under investigation has multiple unknown origins.…

A review of 913 studies involving students with learning disabilities found treatment outcomes were significantly affected by the following violations: teacher effects, establishing criterion levels of instructional performance, reliance on experimental measures, using different pretest and posttest measures, using a sample heterogeneous in age,…

The article examines the concepts of power and control in research design and applies them to a review of the validity of three studies (EC 600 064-066) evaluating the effectiveness of using Irlen tinted lenses with reading-disabled persons. Internal validity, external validity, statistical conclusion validity, and construct validity are…