ABSTRACT
In Chapters 2 and 3, we introduced the multilevel modeling framework, and demonstrated the use of the lme4 R package for fitting two-level models. In Chapter 4, we will expand upon this basic two-level framework by fitting models with additional levels of data structure. As described in Chapter 2, it is conceivable for a level-1 unit, such as students, to be nested in higher-level units, such as classrooms.
