ABSTRACT
The technique of multilevel modeling is now well established and has been incorporated
into most standard statistical packages. It is convenient for present purposes to consider
educational data that exhibit a hierarchical structure of students nested within classrooms
nested within schools-a three-level structure. Other examples are repeated-measures
data with occasions nested within subjects, and surveys with people nested within
households, both of these being two-level data structures. More-complex data structures
such as cross-classifications and multiple-membership structures are extensions for which
models have been developed. Goldstein (2003) provided a detailed exposition with
references to further application areas.