The current study investigated patterns of growth in academic achievement trajectories among American high school students (N = 12,314) that were obtained from a nationally representative, public-use dataset (the High School Longitudinal Study of 2009) in relation to key demographic information (i.e., gender, grade level, socioeconomic status…

This study investigates the effect of multidimensionality on extraction of latent classes in mixture Rasch models. In this study, two-dimensional data were generated under varying conditions. The two-dimensional data sets were analyzed with one- to five-class mixture Rasch models. Results of the simulation study indicate the mixture Rasch model…

It is often assumed that children with learning disabilities (LD) exhibit unique profiles of ability scores that reflect idiosyncratic cognitive strengths and weaknesses. Interpretation of cognitive ability profiles initially focused on visual inspection of subtest scores followed by statistical comparisons to identify significant cognitive…

A newly developed laboratory learning program for high school chemistry courses is discussed, in which students discover the chemical mechanism governing exothermic phenomena during the reaction between a heating agent, namely, calcium oxide (CaO)--aluminum (Al) mixture, and water. Based on prior knowledge of simple heating agents such as CaO, the…

In a signal detection theory (SDT) approach to multiple choice exams, examinees are viewed as choosing, for each item, the alternative that is perceived as being the most plausible, with perceived plausibility depending in part on whether or not an item is known. The SDT model is a process model and provides measures of item difficulty, item…

A mixture extension of Samejima's continuous response model for continuous measurement outcomes and its estimation through a heuristic approach based on limited-information factor analysis is introduced. Using an empirical data set, it is shown that two groups of respondents that differ both qualitatively and quantitatively in their response…

Utilizing the perspective of finite mixture modeling, this note considers whether a finding of a plausible one-parameter logistic model could be spurious for a population with substantial unobserved heterogeneity. A theoretically and empirically important setting is discussed involving the mixture of two latent classes, with the less restrictive…

In 2023, the British Academy commissioned 11 members of its Early Career Researcher Network to write about their experiences of life and work in UK higher education. The essay collection shines a light on the voices, perspectives and journeys of early career researchers, poignantly showcasing the realities and challenges faced by researchers at…

School climate is a well-studied issue in educational research. However, surveys of school climate tend to be analyzed using item-centered as opposed to person-centered methods. The current study evaluated the 2018 South Carolina School Climate Survey using advanced applications of mixture modeling in an attempt to identify latent profiles at the…

Covariates have been used in mixture IRT models to help explain why examinees are classed into different latent classes. Previous research has considered manifest variables as covariates in a mixture Rasch analysis for prediction of group membership. Latent covariates, however, are more likely to have higher correlations with the latent class…

From a physical point of view, the "partial pressure" of a component "i" in a gas mixture is defined as the contribution of molecules "i" to the force per unit area that the molecules of the mixture exert on the wall. The relation pi = x[subscript i]P (where x[subscript i] is the mole fraction of "i" and…

Factor mixture modeling (FMM) has been increasingly used to investigate unobserved population heterogeneity. This study examined the issue of covariate effects with FMM in the context of measurement invariance testing. Specifically, the impact of excluding and misspecifying covariate effects on measurement invariance testing and class enumeration…

The manufacture of metal alloys is ubiquitous, yet infrequently discussed in high school coursework as concepts related to them are often too complex or abstract for beginning science students. However, earlier introduction to metallurgy in classroom settings could promote interest in practical applications of chemistry, physics, and geology due…

Principal stratification is a widely used framework for addressing post-randomization complications. After using principal stratification to define causal effects of interest, researchers are increasingly turning to finite mixture models to estimate these quantities. Unfortunately, standard estimators of mixture parameters, like the MLE, are known…

We used the Stanford education data archive (SEDA) data to examine the heterogeneity among urban school districts in the United States. The SEDA 2.1 includes data sets on students' mathematics (Math) and English language arts (ELA) achievement from 2008 to 2014 at the district level. Growth mixture modeling was used to uncover the underlying…