Growth mixture models (GMMs) are prevalent for modeling unknown population heterogeneity via distinct latent classes. However, GMMs are riddled with convergence issues, often requiring researchers to atheoretically alter the model with cross-class constraints to obtain convergence. We discuss how within-class random effects in GMMs exacerbate…

"Sensor-free" detectors of student affect that use only student activity data and no physical or physiological sensors are cost-effective and have potential to be applied at large scale in real classrooms. These detectors are trained using student affect labels collected from human observers as they observe students learn within…

There is a quantum computing race among the tech giants Google, IBM, and Microsoft, including to a lesser extent Amazon and China's Alibaba. Governments, particularly America and China, are funding work in the area with the concern that quantum computers may soon crack current encryption methods, giving the country that gets there first a major…

Computational thinking (CT) has attracted significant interest among many educators around the globe. Despite this growing interest, research on CT and programming education in elementary school remains at an initial stage. Many relevant studies have adopted only one type of method to assess students' CT, which may lead to an incomplete view of…

A method for evaluating the validity of multicomponent measurement instruments in heterogeneous populations is discussed. The procedure can be used for point and interval estimation of criterion validity of linear composites in populations representing mixtures of an unknown number of latent classes. The approach permits also the evaluation of…

For a certification, licensure, or placement exam, allowing examinees to take multiple attempts at the test could effectively change the pass rate. Change in the pass rate can occur without any change in the underlying latent trait, and can be an artifact of multiple attempts and imperfect reliability of the test. By deriving formulae to compute…

Panel or grouped data are often used to allow for unobserved individual heterogeneity in econometric models via fixed effects. In this paper, we discuss identification of a panel data model in which the unobserved heterogeneity both enters additively and interacts with treatment variables. We present identification and estimation methods for…

Percentage study weights in meta-analysis reveal the contribution of each study toward the overall summary results and are especially important when some studies are considered outliers or at high risk of bias. In meta-analyses of test accuracy reviews, such as a bivariate meta-analysis of sensitivity and specificity, the percentage study weights…

Psychometric measurement models are only valid if measurement invariance holds between test takers of different groups. Global model tests, such as the well-established likelihood ratio (LR) test, are sensitive to violations of measurement invariance, such as differential item functioning and differential step functioning. However, these…

In causal matching designs, some control subjects are often left unmatched, and some covariates are often left unmodeled. This article introduces "rebar," a method using high-dimensional modeling to incorporate these commonly discarded data without sacrificing the integrity of the matching design. After constructing a match, a researcher…

Numerous studies have investigated economies of scale and scope in higher education as a means of providing public and private providers of college and university teaching, research and other services and their stakeholders with knowledge of the cost structures that underpin provision in this economically and socially important sector. However,…

Some IRT models can be equivalently modeled in alternative frameworks such as logistic regression. Logistic regression can also model time-to-event data, which concerns the probability of an event occurring over time. Using the relation between time-to-event models and logistic regression and the relation between logistic regression and IRT, this…

A novel method of measuring the coefficients of kinetic and rolling friction is proposed. The method is simple to implement and reliable. Samples of measurements and calculations are presented.

Successful mathematical problem-solving relies on choices about how best to represent and solve problems. In this article, a range of methods and strategies are presented for solving a single mathematical problem, including novel methods posed by in-service teachers at one Australian university. The variety of problem-solving strategies rely on…

In fact, ever since Seymour Papert (famous in his later years for constructionism, a learning theory that married conceptual constructivism with concrete experience) created Logo programming, many schools have been coding using Logo, the educational computer programming software that has the famous 'turtle' on the computer screen. Importantly,…