ABSTRACT
Multilevel models are becoming commonplace in education to account for the clustering of students within classrooms. Multilevel models have been developed in numerous fields to account for the clustering of observations within other units, such as repeated measures within students, or classrooms within schools (see overview by Kreft & de Leeuw, 1998). In this chapter, it is assumed that readers have a general familiarity with multilevel models. Practical examples of how to fit multilevel models are numerous (e.g., West, Welch, & Galecki, 2007), with one of the best and most cited being Singer (1998). An excellent conceptual introduction to multilevel methods with connections to different historical traditions can be found in Kreft and de Leeuw (1998). More complete technical accounts of multilevel models can be found in Raudenbush and Bryk (2002), Goldstein (2003), and Snijders and Bosker (1999).
