Background: Randomized controlled trials (RCTs), or experiments, are the gold standard for intervention evaluation. However, the main appeal of RCTs--the clean identification of causal effects--can be compromised by interference, when one subject's actions can influence another subject's behavior or outcomes. In this paper, we formalize and study…

The interaction of quantitative and qualitative methodology in the mixed methods research (MMR) is analysed in a context of distinctions of the meanings between the terms typically used for description, combination, and integration. The interaction in the phases that precede the results, and their interpretation is considered. As an indicator of…

Examining teachers' knowledge on a large scale involves addressing substantial measurement and logistical issues; thus, existing teacher knowledge assessments have mainly consisted of selected-response items because of their ease of scoring. Although open-ended responses could capture a more complex understanding of and provide further insights…

The definition of what constitutes a conflict, in terms of both time and events, has been consistently debated in the historical study of social phenomena. What has become increasingly clear, however, is that the methods used to define it are generally biased as they are highly dependent on the perceptions of the researchers who establish them.…

Recent metascience suggests that motor behavior research may be underpowered, on average. Researchers can perform a priori power analyses to ensure adequately powered studies. However, there are common pitfalls that can result in underestimating the required sample size for a given design and effect size of interest. Critical evaluation of power…

This article explains the basic ideas and practical challenges in clinical trials of new medicines to show the practical application of statistics in the real-world. The article explores the key considerations for the objectives and design of clinical trials and how these relate to the statistical investigation process. The article also includes…

This paper delves into statistical disparities between human-written and ChatGPT-generated texts, utilizing an analysis of Shannon's equitability values, and token frequency. Our findings indicate that Shannon's equitability can potentially be a differentiating factor between texts produced by humans and those generated by ChatGPT. Additionally,…

In causal mediation studies that decompose an average treatment effect into indirect and direct effects, examples of post-treatment confounding are abundant. In the presence of treatment-by-mediator interactions, past research has generally considered it infeasible to adjust for a post-treatment confounder of the mediator-outcome relationship due…

Beginning with debates about the effects of smoking on lung cancer, sensitivity analyses characterizing the hypothetical unobserved conditions that can alter statistical inferences have had profound impacts on public policy. One of the most ascendant techniques for sensitivity analysis is Oster's (2019) coefficient of proportionality, which…

Methods for optimal factor rotation of two-facet loading matrices have recently been proposed. However, the problem of the correct number of factors to retain for rotation of two-facet loading matrices has rarely been addressed in the context of exploratory factor analysis. Most previous studies were based on the observation that two-facet loading…

The recent commentary by Beaujean and Farmer (2020) on the original paper by Dixon et al. (2019) serves a cautionary tale of selective p-values, the law of small N sizes, and the type-II error. We believe these authors have crafted a somewhat questionable argument in which only 57% of the original Dixon et al. data were re-analyzed, based on a…

Methodologists serve a critical role in the research enterprise. It is our contention that there is an imbalance between the need for methodologists and the needs of methodologists. Providing methodological support to substantive research and methodological reviews are critical service areas that strengthen the entire research enterprise.…

Human creativity finds in artistic practices one of its most admirable forms. Most of the studies about artistic practices have used qualitative approaches, focusing on the conceptual structures conveyed by the artwork. Few studies have used quantitative approaches with the potential to be generalized. This study has focused on developing a…

Factor score regression has recently received growing interest as an alternative for structural equation modeling. However, many applications are left without guidance because of the focus on normally distributed outcomes in the literature. We perform a simulation study to examine how a selection of factor scoring methods compare when estimating…

Previous simulation studies of randomization tests applied in single-case educational intervention research contexts have typically focused on A-to-B phase changes in means/levels. In the present simulation study, we report the results of two multiple-baseline investigations, one targeting between-phase changes in slopes/trends and the other…