With large-scale wicked problems threatening our world, the integration of sustainability into teacher professional learning is systemically lacking in the United States. The purpose of this case study was to understand the impact of a multi-session, sustainability-related professional learning program on twelve PreKindergarten-8th grade educators…

Background: Cluster-randomized experiments that assign intact groups such as schools or school districts to treatment conditions are increasingly common in educational research. Such experiments are inherently multilevel designs whose sensitivity (statistical power and precision of estimates) depends on the variance decomposition across levels.…