Estimating confidence intervals (CIs) for the correlation has been a challenge because the correlation sampling distribution changes depending on the correlation magnitude. The Fisher z-transformation was one of the first attempts at estimating correlation CIs but has historically shown to not have acceptable coverage probability if data were…

Background/Context: Confirmatory factor analysis (CFA) model is a commonly adopted framework to estimate and test a measurement model. Once a well-fitting final CFA model is selected, the selected model may be used to test structural relationships of the latent constructs with other variables, to construct a test with desired reliability and…

Partially specified correlation matrices (not to be confused with matrices with missing data or EM-correlation matrices) can appear in research settings such as integrative data analyses, quantitative systematic reviews or whenever the study design only allows for the collection of certain variables. Although approaches to fill in these missing…

Cross-national comparisons of educational achievement rely upon each participating country collecting nationally representative data. While obtaining high response rates is a key part of reaching this goal, other potentially important factors may also be at play. This paper focuses on one such issue--exclusion rates--which has received relatively…

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…

A wide variety of methodological choices and situations can affect the quality of peer nomination measurements but have not received adequate study. This article begins by focusing on systematic nominator missingness as an example of one such situation. We reanalyzed findings from a recent study by Bukowski, Dirks, Commisso, Velàsquez, and Lopez…

This article analyses and discusses dilemmas, ambivalences and problematic issues related to research ethics. This is done firstly by making a distinction between procedural research ethics and particularistic research ethics. Such a distinction reflects a theoretical construction and generalization. In practice, there can be a very close…

In this Perspectives article, the author grapples with the personal challenges of attempting to do ethical and high-quality research in the post world of the maturing 21st century. Among the challenges addressed are matters of purported relevance of research, equity research conducted by nonmembers of equity-seeking groups, the impact of rankings…

Determining the number of factors in exploratory factor analysis is arguably the most crucial decision a researcher faces when conducting the analysis. While several simulation studies exist that compare various so-called factor retention criteria under different data conditions, little is known about the impact of missing data on this process.…

Meta-studies are often conducted on empirical findings obtained from overlapping samples. Sample overlap is common in research fields that strongly rely on aggregated observational data (eg, economics and finance), where the same set of data may be used in several studies. More generally, sample overlap tends to occur whenever multiple estimates…

Scientific progress depends on the integrity of data and research findings. Intentionally distorting research data and findings constitutes scientific misconduct and introduces falsehoods into the scientific record. Unintentional distortions arising from questionable research practices (QRPs), such as unsystematically deleting outliers, pose…

Publication pressure has been touted to promote questionable research practices (QRP) and scientific or research misconduct (RM). However, logically attractively as it is, there is no unequivocal evidence for this notion, and empirical studies have produced conflicting results. Other than difficulties in obtaining unbiased empirical data, a direct…

Recurrent pain and school failures are common problems in children visiting the school nurses office. The overall aim of the current study was to investigate the relationship between recurrent pain and academic achievement in school-aged children. Literature was searched in seven electronic databases and in relevant bibliographies. Study…

Missing data are ubiquitous in studies examining preventive interventions. This missing data need to be handled appropriately for data analyses to yield unbiased results. After a brief discussion of missing data mechanisms, inappropriate missing data treatments and appropriate missing data treatments, we review the current state of missing data…

Background: Interventions for offenders with intellectual disabilities (ID) have used cognitive variables as measures of treatment outcome. However, the relevance of cognitive variables to offending in people with intellectual disabilities is unclear. This review aimed to evaluate the evidence for a relationship between cognitive variables and…