Background: Power analyses for a cluster-randomized trial (CRT) require estimates of additional design parameters beyond those needed for an individually randomized trial. In a 2-level CRT, there are two sample sizes, the number of clusters and the number of individuals per cluster. The intraclass correlation (ICC), or the proportion of variance…

The purposes of this manuscript are to identify common statistical mistakes in sport management, and to provide scholars with suggestions on how to develop and improve the quality of quantitative research. We have reviewed articles published from 2001 to 2017 in the "Journal of Sport Management," "Sport Management Review,"…

The use of advanced quantitative methods within mixed methods research has been investigated in a limited capacity. In particular, hierarchical linear models are a popular approach to account for multilevel data, such as students within schools, but its use and value as the quantitative strand in a mixed methods study remains unknown. This article…

While other fields such as statistics and education have examined various issues with quantitative work, few studies in physics education research (PER) have done so. We conducted a two-phase study to identify and to understand the extent of these issues in quantitative PER. During phase 1, we conducted a focus group of three experts in this area,…

This report presents a review of the statistical practices of 30 journals representative of the second language field. A review of 150 articles showed a number of prevalent statistical violations including incomplete reporting of reliability, validity, non-significant results, effect sizes, and assumption checks as well as making inferences from…

This research study aims to evaluate the graduate theses and articles conducted on the concept of instructional leadership over the period between 2002 and 2017 in Turkey by means of methodological and statistical analysis techniques. In the study, which is configured by using the case study design as one of the qualitative research methods, the…

Value-added estimates of teacher or school quality are increasingly used for both high- and low-stakes accountability purposes, making understanding of their limitations critical. A review of the recent value-added literature suggests three concerns with the state of the research. First, the issues receiving the most research attention have not…

Quantitative research enjoys heightened esteem among policy-makers, media, and the general public. Whereas qualitative research is frequently dismissed as subjective and impressionistic, statistics are often assumed to be objective and factual. We argue that these distinctions are wholly false; quantitative data is no less socially constructed…

Multilevel models are an increasingly popular method to analyze data that originate from a clustered or hierarchical structure. To effectively utilize multilevel models, one must have an adequately large number of clusters; otherwise, some model parameters will be estimated with bias. The goals for this paper are to (1) raise awareness of the…

Meta-analysis is a statistical method that is increasingly utilized to combine and compare the results of previous primary studies. However, because of the lack of comprehensive guidelines for how to use meta-analysis, many meta-analysis studies have failed to consider important aspects, such as statistical programs, power analysis, publication…

"What works" policies are the latest incarnation of best practices in educational research. Instituted by various organisations internationally, they define what kind of research counts as "evidence" for reform-oriented decision-making. While some countries rely on systematic analyses and meta-analyses, the U.S. favours primary…

Outdoor adventure education (OAE) has a long history of being credited with the personal and social development (PSD) of its participants. PSD is notoriously difficult to measure quantitatively, yet stakeholders demand statistical evidence that given approaches to eliciting PSD are effective in their methods. Rightly or wrongly, many stakeholders…

Given the American Psychological Association's strong recommendation to always report effect sizes in research, scholars have a responsibility to provide complete information regarding their findings. The purposes of this study were to (a) determine the frequencies with which different effect sizes were reported in published, peer-reviewed…

Applied linguists have turned increasingly in recent years to meta-analysis as the preferred means of synthesizing quantitative research. The first step in the meta-analytic process involves defining a domain of interest. Despite its apparent simplicity, this step involves a great deal of subjectivity on the part of the meta-analyst. This article…

In order to better assist practitioners and better serve persons with autism spectrum disorders (ASD) and their families, it is vital for professionals to systematically evaluate the existing body of literature and synthesize its scientific evidence, so that the efficacy of research can be translated to evidence-based practices (EBPs) (Wheeler,…