A robust body of research has identified associations between positive teacher-child relationships--characterized by high levels of closeness and low levels of conflict--and children's academic achievement in elementary school (e.g. Roorda, 2012). Additional studies find that high-quality teacher-child relationships may promote academic resilience…

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.…

There is continuing controversy about the optimal or appropriate age at which children should start school. The purpose of this study is to examine the relationship between age and achievement. It is an attempt to evaluate the hypothesis that older students fare better academically than their younger classmates. Findings indicate that on average…