Using PROC MIXED in Hierarchical Linear Models: Examples from two- and three-level school-effect analysis, and meta-analysis research
نویسندگان
چکیده
The study presents useful examples of fitting hierarchical linear models using the PROC MIXED statistical procedure in the SAS system. Hierarchical linear models are quite common in social science studies, in particular educational research, due to naturally occurring hierarchies or clusters (e.g., students belong to classes which are nested in schools). Despite their prevalence, the SAS PROC MIXED does not seem to be fully recognized of its usefulness in analyzing these models. The current paper discusses the advantages of fitting the hierarchical linear models to multilevel data sets and the convenience of conducting such analysis with PROC MIXED. Examples from twoand threelevel school-effects analysis, and meta-analysis research are introduced. Particular focus will be on practical usage of the program: how the program scripts are constructed in relation to the model, and how to interpret the output in the context of the research question.
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