ABSTRACT
Statistical techniques for the analysis of nested data structures are increasing in popularity (Bryk & Raudenbush, 1992; Goldstein, 1995; Kreft & de Leeuw, 1998; Little, Schnabel, & Baumert, 2000). These techniques, which we refer to as multilevel modeling (MLM), have been proposed as a general data-analytic strategy for the exploration of longitudinal data, the effects of community-based interventions, the outcomes of clinical trials, effect sizes in meta-analysis, school effectiveness research, and family process or couples research.
