Background: The absence of Physical Education (PE) from the South African school curriculum before its reintroduction in recent years contributed to health concerns regarding the low physical activity (PA) levels of children and adolescents in South Africa. Purpose: This study evaluated the effects of a once-a-week enhanced quality PE programme on…

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.…