Single-case designs (SCDs) are a class of research methods for evaluating the effects of academic and behavioral interventions in educational and clinical settings. Although visual analysis is typically the first and main method for primary analysis of data from SCDs, quantitative methods are useful for synthesizing results and drawing systematic…

Background: As the body of scientific evidence about what works in education grows, so does the need to effectively communicate that evidence to policy-makers and practitioners. Websites and clearinghouses such as the "What Works Clearinghouse" (WWC), "Evidence for ESSA," "Blueprints for Healthy Youth Development,"…

Purpose: Instructional leadership has assumed steadily increasing importance within the general role set of principals over the past 60 years. One persisting finding within this corpus of studies concerns the consistently higher ratings obtained by female principals on instructional leadership when compared with their male counterparts. This…

This methodological brief introduces basic procedures and issues for conducting a high-quality meta-analysis in gifted education. Specifically, we discuss issues such as how to select a topic and formulate research problems, search for and identify qualified studies, code studies and extract data, choose and calculate effect sizes, analyze data,…

Evidence-based insight on the effectiveness of reminders in web-based data collection in online panels is scarce. Thirty-eight studies were conducted in three different online panels to examine the effect of reminders on response rates, retention rates, and two facets of response quality (i.e., item omissions and response nondifferentiation). The…

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…

This meta-analysis examined over 40 years of research on interracial interactions by exploring 4 types of outcomes: explicit attitudes toward interaction partners, participants' self-reports of their own emotional state, nonverbal or observed behavior, and objective measures of performance. Data were collected from 108 samples (N = 12,463)…

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…

Some methodological issues in the study of levels of knowledge are reviewed, and needs for further research are explored, drawing on an analysis of 12 studies reported since the late 1970s. In the 12 studies, 16 quantitative experiments were conducted. These were assessed for internal and external validity. Analysis revealed some shortcomings in…