Special Education and Related Services: What Have We Learned From Meta-Analysis?

Although special education research has been subject to criticism in recent years, development of best practice continues to rely on accumulation of research findings. Meta-analysis allows interpretation of accumulated research in unique ways; some 24 meta-analyses, in or related to special education interventions, have become available over the years. The purpose of this article is to review each of them briefly and draw tentative conclusions about the relative power of interventions as determined by magnitude of mean effect size for each.