This Digest provides a review and applications of the concepts of normal distribution, standard deviation, effect size, and translation of effect size into percentile gain, the foundations for the understanding of meta analytic results. Meta analysis is a statistical technique that enables the results of a number of studies to be combined to…

Meta-analysis is a collection of systematic techniques for resolving apparent contradictions in research findings. Meta-analysts translate results from different studies to a common metric and statistically explore the relations between study characteristics and findings. Since G. Glass first used the term "meta-analysis" in 1976, it has…

In an effort to provide information about the effect of computer use in schools on student achievement, attitudes, dropout rate, and learning time, a review of instructional computing research analyzed studies done between 1980 and 1987 using statistical summary procedures. Reviewers used a meta analysis procedure to calculate effect size as they…