The number of meta-analyses of aggregate data has dramatically increased due to the facility of obtaining data from publications and the development of free, easy-to-use, and specialised statistical software. Even when meta-analyses include the same studies, their results may vary owing to different methodological choices. Assessment of the…

When performing an aggregate data meta-analysis of a continuous outcome, researchers often come across primary studies that report the sample median of the outcome. However, standard meta-analytic methods typically cannot be directly applied in this setting. In recent years, there has been substantial development in statistical methods to…

Meta-analysis and structural equation modeling (SEM) are 2 of the most prominent statistical techniques employed in the behavioral, medical, and social sciences. They each have their own well-established research communities, terminologies, statistical models, software packages, and journals ("Research Synthesis Methods" and…

Purpose: Instructional leadership has been an active area of educational administration research over the past 30 years. However, there has been significant divergence in how instructional leadership has been conceptualized over time. The purpose of this paper is to present a comprehensive review of 25 years of quantitative instructional…

The purpose of this study is both to gather the experimental studies which investigate the effect of creative drama on the attitudes of students towards the courses and to synthesize the findings of these studies. The studies within the scope of this current research were obtained from various databases such as "ProQuest Citations, Council of…

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,…

Purpose: The purpose of this paper is to improve the understanding of psychological factors that influence inquiry-based leadership. This study investigates how affective attitude, experienced social pressure, and self-efficacy relate to aspects of inquiry-based school leadership. A school leader's inquiry habit of mind, data literacy, and the…

Systematic reviews of literature are studies that strategically search for published research on a specific topic in order to synthesize what is known about the topic. This systematic review describes 157 articles on synchronous online learning (SOL) from thirty-four different countries on instructional setting, content areas, participant…

This study attempts to reveal whether different applications have effects on retention and attitude of pre-service teachers studying in various branches in Turkey through meta-analysis. Studies carried out between 2005 and 2015 in national and international area, 324 (218 articles, 106 theses) were chosen. However, 23 studies (9 retention and 14…

Students with disabilities experience poorer post-school outcomes compared with their peers without disabilities. Existing experimental literature on "what works" for improving these outcomes is rare; however, a rapidly growing body of research investigates correlational relationships between experiences in school and post-school…

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…

This succinct and jargon-free introduction to effect sizes gives students and researchers the tools they need to interpret the practical significance of their results. Using a class-tested approach that includes numerous examples and step-by-step exercises, it introduces and explains three of the most important issues relating to the practical…

Meta-analysis of studies with two groups and two measurement occasions must employ order-one effect size indices to represent study outcomes. Especially with non-random assignment, non-equivalent control group designs, a statistical analysis restricted to post-treatment scores can lead to severely biased conclusions. The 109 primary studies…

Although they test somewhat different hypotheses, analysis of gain scores (or its repeated-measures analog) and analysis of covariance are both common methods that researchers use for pre-post data. The results of the two approaches yield non-comparable outcomes, but since the same generic data are used, it is possible to transform the test…

There are both quantitative and methodological techniques that foster the development and maintenance of a cumulative knowledge base within the psychological sciences. Most noteworthy of these techniques is meta-analysis, which allows for the synthesis of summary statistics drawn from multiple studies when the original data are not available.…