In educational and psychological research, we are often interested in discrete latent states of individuals responding to an assessment (e.g., proficiency or non-proficiency on educational standards, the presence or absence of a psychological disorder). Diagnostic classification models (DCMs; also called cognitive diagnostic models [CDMs]) are a…

In this study, we re-analyze recent empirical research on replication from a meta-analytic perspective. We argue that there are different ways to define "replication failure," and that analyses can focus on exploring variation among replication studies or assess whether their results contradict the findings of the original study. We…

Although Montessori is the most common unconventional education model, no multi-state study has compared standardized test proficiency of Montessori schools with districts. Here we report on this for the 10 states/regions with the most public Montessori schools (n = 195). In 3rd grade, Montessori schools were less proficient in math but more…