In mixed methods approaches, statistical models are used to identify "nested" cases for intensive, small-n investigation for a range of purposes, including notably the examination of causal mechanisms. This article shows that under a commonsense interpretation of causal effects, large-n models allow no reliable conclusions about effect…

In carrying out surveys involving sensitive characteristics, randomized response models have been considered among the best techniques since they provide the maximum privacy protection to the respondents and procure honest responses. Over the years, researchers have carried out studies on the estimation of proportions of the population possessing…

Toward the goal of more rapid knowledge accumulation via better meta-analyses, this article explores statistical approaches intended to increase the precision and comparability of effect sizes from education research. The featured estimate of the proposed approach is a standardized mean difference effect size whose numerator is a mean difference…

It is widely believed that regression models for binary responses are problematic if we want to compare estimated coefficients from models for different groups or with different explanatory variables. This concern has two forms. The first arises if the binary model is treated as an estimate of a model for an unobserved continuous response and the…

As a result of the COVID-19 pandemic, at-home testing has become a popular delivery mode in many testing programs. When programs offer at-home testing to expand their service, the score comparability between test takers testing remotely and those testing in a test center is critical. This article summarizes statistical procedures that could be…

This article develops new closed-form variance expressions for power analyses for commonly used difference-in-differences (DID) and comparative interrupted time series (CITS) panel data estimators. The main contribution is to incorporate variation in treatment timing into the analysis. The power formulas also account for other key design features…

Two approaches for the statistical analysis of social network generation are widely used; the tie-oriented exponential random graph model (ERGM) and the stochastic actor-oriented model (SAOM) or Siena model. While the choice for either model by empirical researchers often seems arbitrary, there are important differences between these models that…

There are many well-known or new methods to adjust statistical tests for multiplicity. This article provides an illustration helping lecturers or consultants to remember the differences of three important multiplicity adjustment methods and to explain them to non-statisticians.

Teaching simple circuits and Ohm's law to students in the introductory classroom has been extensively investigated through the common practice of using incandescent light bulbs to help students develop a conceptual foundation before moving on to quantitative analysis. However, the bulb filaments' resistance has a large temperature dependence,…

Between-subject design surveys are a powerful means of gauging public opinion, but critics rightly charge that closed-ended questions only provide slices of insight into issues that are considerably more complex. Qualitative research enables richer accounts but inevitably includes coder bias and subjective interpretations. To mitigate these…

Processes of naturalistic reading and writing are based on complex linguistic input, stretch-out over time, and rely on an integrated performance of multiple perceptual, cognitive, and motor processes. Hence, naturalistic reading and writing performance is nonstationary and exhibits fluctuations and transitions. However, instead of being just…

Indirect treatment comparisons are useful to estimate relative treatment effects when head-to-head studies are not conducted. Statisticians at the National Centre for Pharmacoeconomics Ireland (NCPE) and Scottish Medicines Consortium (SMC) assess the clinical and cost-effectiveness of new medicines as part of multidisciplinary teams. We describe…

Bad smells affect maintainability and performance of model-to-model transformations. There are studies that define a set of transformation bad smells, and some of them propose techniques to recognize and--according to their complexity--fix them in a (semi)automated way. In academia it is necessary to make students aware of this subject and provide…

Statistical methods are indispensable to the practice of science. But statistical hypothesis testing can seem daunting, with P-values, null hypotheses, and the concept of statistical significance. This article explains the concepts associated with statistical hypothesis testing using the story of "the lady tasting tea," then walks the…

This technical supplement to the Supplemental Nutrition Assistance Program (SNAP) Employment and Training (E&T) evaluation final reports presents details of the technical approach used for creating analysis variables and estimating impacts of treatment group services on outcomes, including employment, earnings, and SNAP participation. It also…