This article proposes a latent variable regression four-level hierarchical model (LVR-HM4) that uses a fully Bayesian approach. Using multisite multiple-cohort longitudinal data, for example, annual assessment scores over grades for students who are nested within cohorts within schools, the LVR-HM4 attempts to simultaneously model two types of…

Despite the potential of differentiated curricula to enhance learning, limited research exists that documents their impact on Grade 3 students of all ability levels. To determine if there was a difference in achievement between students involved in 16 weeks of predifferentiated, enriched mathematics curricula and students using their district's…