To better understand the longitudinal relations between risk and relationship variables during early to middle adolescence, we employed latent variable cross-lagged panel models using data (N = 1,050) from the National Institute of Child Health and Human Development Study. Results showed self-reported individual risk behavior ([beta] = 0.77-0.88)…

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.…