Over the last decade, there has been a 10-fold increase in the number of published systematic reviews of prevalence. In meta-analyses of prevalence, the summary estimate represents an average prevalence from included studies. This estimate is truly informative only if there is no substantial heterogeneity among the different contexts being pooled.…

This study aims to introduce network meta-analysis (NMA) to provide educational researchers with an extended view of the reviewing educational research. Meta-analytic methods have been widely used in educational research reviews. However, weaknesses have emerged in the multi-group comparison analysis of educational studies where different…

As reporting of effect sizes in evaluation studies has proliferated, researchers and consumers of research need tools for interpreting or benchmarking the magnitude of those effect sizes that are relevant to the intervention, target population, and outcome measure being considered. Similarly, researchers planning education studies with social and…

High-quality systematic literature reviews provide a systematic process for identifying, synthesizing, and critiquing multiple studies and, in turn, inform theory, research, practice, and policy. With a focus on special education systematic reviews, we propose four core principles (i.e., coherence, contextualization, generativity, and…

This methodological guidance article discusses the elements of a high-quality meta-analysis that is conducted within the context of a systematic review. Meta-analysis, a set of statistical techniques for synthesizing the results of multiple studies, is used when the guiding research question focuses on a quantitative summary of study results. In…

It is now widely accepted that the standard inferential toolkit used by the scientific research community--null-hypothesis significance testing (NHST)--is not fit for purpose. Yet despite the threat posed to the scientific enterprise, there is no agreement concerning alternative approaches for evidence assessment. This lack of consensus reflects…

While the systematic review process is intended to maximize objectivity and limit researchers' biases, examples remain of discordant recommendations from meta-analyses. Current guidelines to explore discrepancies assume the variation is produced by methodological differences and thus focus only on the study process. Because heterogeneity of…

This response aims to critically evaluate the methodology and aims of the meta-analytic review written by Maggin and Johnson (2014). The present authors systematically provide responses for each of the original criticisms and highlight concerns regarding Maggin and Johnson's methodology, while objectively describing the current state of evidence…

Qualitative research is a broad term encompassing many methods. Critiques of the field of qualitative research argue that while individual studies provide rich descriptions and insights, the absence of connections drawn between studies limits their usefulness. In response, qualitative meta-synthesis serves as a design to interpret and synthesise…

Research has shown that forest plots are a gold standard in the visualization of meta-analytic results. However, research on the general interpretation of forest plots and the role of researchers' meta-analysis experience and field of study is still unavailable. Additionally, the traditional display of effect sizes, confidence intervals, and…

This paper examines sources of potential bias in systematic reviews and meta-analyses which can distort their findings, leading to problems with interpretation and application by practitioners and policymakers. It follows from an article that was published in the "Canadian Journal of Communication" in 1990, "Integrating Research…

Overlap-based measures are increasingly applied in the synthesis of single-subject research. This article considers two criticisms of overlap-based metrics, specifically that they do not measure magnitude of effect and do not adequately correspond with visual analysis. It is argued that these criticisms are based on fundamental misconceptions…

In several subdomains of the social, behavioral, health, and human sciences, research questions are increasingly answered through mixed methods studies, combining qualitative and quantitative evidence and research elements. Accordingly, the importance of including those primary mixed methods research articles in systematic reviews grows. It is…

Background: Historically, significant advances in scientific understanding have followed advances in measurement and observation. As the resolving power of an instrument increased, so have gains in the understanding of the phenomena being observed. Modern interactive systems are potentially the new "microscopes" when they are…

Confidence intervals (CIs) and effect sizes are essential to encourage meta-analytic thinking and to accumulate research findings. CIs provide a range of plausible values for population parameters with a degree of confidence that the parameter is in that particular interval. CIs also give information about how precise the estimates are. Comparison…