Identifying mediators in variable chains as part of a causal mediation analysis can shed light on issues of causation, assessment, and intervention. However, coefficients and effect sizes in a causal mediation analysis are nearly always small. This can lead those less familiar with the approach to reject the results of causal mediation analysis.…

To date, the theory of intersectionality has largely guided qualitative efforts in social science and education research. Translating the construct to new methodological approaches is inherently complex and challenging, but offers the possibility of breaking down silos that keep education researchers with similar interests--but different…

Autocorrelation and partial autocorrelation, which provide a mathematical tool to understand repeating patterns in time series data, are often used to facilitate the identification of model orders of time series models (e.g., moving average and autoregressive models). Asymptotic methods for testing autocorrelation and partial autocorrelation such…

This data file documentation accompanies new data files for the High School Longitudinal Study of 2009 (HSLS:09) Postsecondary Education Transcript Study and Student Financial Aid Records Collection (PETS-SR). HSLS:09 follows a nationally representative sample of students who were ninth-graders in fall 2009 from high school into postsecondary…

Recent studies show cluster randomized trials may be well powered to detect mediation or indirect effects in multilevel settings. However, literature has rarely provided guidance on designing cluster-randomized trials aim to assess indirect effects. In this study, we developed closed-form expression to estimate the variance of and the statistical…

The resources needed to conduct high-quality and large-scale survey research are often beyond the reach of institutional researchers and higher education analysts. However, the National Center for Education Statistics (NCES) provides many national student surveys that researchers can utilize. We outline four NCES studies--the High School…

Reproducibility crises have arisen in psychology and other behavioral sciences, spurring efforts to ensure research findings are credible and replicable. Although reforms are occurring at professional levels in terms of new publication parameters and open science initiatives, the credibility and reproducibility of undergraduate research deserves…

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…

This article discusses the sample size requirements for the interaction, row, and column effects, respectively, by forming a linear contrast for a 2×2 factorial design for fixed-effects heterogeneous analysis of variance. The proposed method uses the Welch t test and its corresponding degrees of freedom to calculate the final sample size in a…

University league tables give the image that there is a single dimension along which institutions can be placed. Most derive rankings from an aggregate score of multiple items, which often include opinion responses which has the potential to introduce sampling bias. This paper explores what happens when the two issues of dimensionality and…

Successful testing programs rely on high-quality test items to produce reliable scores and defensible exams. However, determining what statistical screening criteria are most appropriate to support these goals can be daunting. This study describes and demonstrates cost-benefit analysis as an empirical approach to determining appropriate screening…

Structured means analysis is a very useful approach for testing hypotheses about population means on latent constructs. In such models, a z test is most commonly used for testing the statistical significance of the relevant parameter estimates or of the differences between parameter estimates, where a z value is computed based on the asymptotic…

This article addresses the problem of estimating the proportion Pi[subscript S] of the population belonging to a sensitive group using optional randomized response technique in stratified sampling based on Mangat model that has proportional and Neyman allocation and larger gain in efficiency. Numerically, it is found that the suggested model is…

Confidence intervals for effect sizes (CIES) provide readers with an estimate of the strength of a reported statistic as well as the relative precision of the point estimate. These statistics offer more information and context than null hypothesis statistic testing. Although confidence intervals have been recommended by scholars for many years,…

Most study samples show less variability in key variables than do their source populations due most often to indirect selection into study participation associated with a wide range of personal and circumstantial characteristics. Formulas exist to correct the distortions of population-level correlations created. Formula accuracy has been tested…