Generalizability theory is a modern and powerful framework for conducting reliability analyses. It is flexible to accommodate both random and fixed facets. However, there has been a relative scarcity in the practical literature on how to handle the fixed facet case. This article aims to provide practitioners a conceptual understanding and…

Cluster-randomized trials have been widely used to evaluate the treatment effects of interventions on student outcomes. When interventions are implemented by teachers, researchers need to account for the nested structure in schools (i.e., students are nested within teachers nested within schools). Schools usually have a very limited number of…

Clustering methods are often used in physics education research (PER) to identify subgroups of individuals within a population who share similar response patterns or characteristics. Among these, k-means (or k-modes, for categorical data) is one of the most commonly used clustering methods in PER. This algorithm, however, is distance-based rather…