Multilevel models have become very common in social research, however, there are aspects of these models that are explored only infrequently in published articles that appear in academic journals, but which rarely make their way into courses and training materials. The author's view is that multilevel modeling offers powerful tools for understanding the multilevel data that social researchers often confront. For example, researchers are often interested in studying outcomes for diverse groups of children in different schools, residents of diverse and different neighborhoods, or individuals or...