Research articles (n=174) published in the "Journal of Learning Disabilities" from 1989 through 1993 were analyzed and coded by type of research design and statistical technique used. Eighty percent of the research designs were nonintervention methods; 55% of all statistical techniques were coded as primary, 32% were intermediate, and…

Examination of methodological issues in the design and interpretation of studies on the genetics of reading disability suggests three tests of increasing rigor for determining whether reading score distributions are categorical and thus not subject to analyses which assume a continuous normal distribution. Also noted are interactive relationships…

This paper reviews criticism on misinterpretation and overuse of significance testing in the social sciences and examines use of effect size measures to enhance interpretation of significance testing. Review of typical effect size measures and their application is followed by analysis of use of effect size measures in studies reported over 10…

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…