In late November 2020, there was a flurry of media coverage of two companies' claims of 95% efficacy rates of newly developed COVID-19 vaccines, but information about the confidence interval was not reported. This paper presents a way of teaching the concept of hypothesis testing and the construction of confidence intervals using numbers announced…

Educational inequalities are one of the most critical issues facing contemporary societies. While there is a substantial body of quantitative literature tracking inequalities in education based on students' characteristics, an emerging literature is applying the concept of intersectionality to acknowledge the multiple, overlapping impact of these…

A procedure that can be used to evaluate the variance inflation factors and tolerance indices in linear regression models is discussed. The method permits both point and interval estimation of these factors and indices associated with explanatory variables considered for inclusion in a regression model. The approach makes use of popular latent…

In this article, alternative randomized response models are proposed, which make use of sum of quantitative scores generated from two decks of cards being used in a survey. The proposed methods are compared to the Odumade and Singh and Singh and Grewal models through a simulation study. It is shown that the modified methods can be used more…

Cognitive modelling shares many features with statistical modelling, making it seem trivial to borrow from the practices of robust Bayesian statistics to protect the practice of robust cognitive modelling. We take one aspect of statistical workflow--prior predictive checks--and explore how they might be applied to a cognitive modelling task. We…

Lean is a process improvement approach to improve organization's efficiency by identifying and eliminate non-value-added activities, while Six Sigma is a methodology focused on reduction of process variation. The integration of both, namely Lean Six Sigma (LSS) drives organization on waste elimination, variation reduction and value creation, which…

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…

The ability to collaborate with culturally diverse groups is essential, not only to further scientific knowledge but also to solve complex global problems. However, not all students have opportunities to develop intercultural competencies through study abroad programs, due to various issues such as cost, rigid curriculum, and unrelated field of…

A novel undergraduate analytical chemistry experiment involving the identification and quantification of linalool in essential oils was developed. The experiment uses the internal standard method with headspace solid phase microextraction (SPME) and gas chromatography--mass spectrometry (GC-MS). This method is applicable to any linalool-containing…

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…

Design literacy is an emerging research field that is gaining attention among scholars today. Credit goes to the growing acceptance of design thinking in various disciplines beyond design. Design literacy develops natural abilities in everyone to solve real-world, wicked problems by supporting the cognitive development of concrete (making things)…

The four-parameter logistic (4PL) Item Response Theory (IRT) model has recently been reconsidered in the literature due to the advances in the statistical modeling software and the recent developments in the estimation of the 4PL IRT model parameters. The current simulation study evaluated the performance of expectation-maximization (EM),…

The application of diagnostic classification models (DCMs) in the field of educational measurement is getting more attention in recent years. To make a valid inference from the model, it is important to ensure that the model fits the data. The purpose of the present study was to investigate the performance of the limited information…

Learning in asynchronous online environments has gained importance over the last several decades, and educational environment shifts from the COVID-19 pandemic appear to have increased this need. Science educators and students need information about which approaches work in the asynchronous environment where informal feedback tends to be reduced,…

Purpose: This study examined the psychometric properties of intention to drop out and study satisfaction measures for first-year South African students. The factorial validity, item bias, measurement invariance and reliability were tested. Design/methodology/approach: A cross-sectional design was used. For the study on intention to drop out, 1,820…