Research aim was to reveal peculiarities of the education of social skills among senior high school age students in physical education classes. We hypothesized that after the end of the educational experiment the senior high school age students will have more developed social skills in physical education classes. Participants in the study were 51…

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.…