Modeling Intraindividual Variability With Repeated Measures Data

Chapter 6

Fitting Individual Growth Models Using SAS PROC MIXED

Judith D. Singer

Harvard University

PROC MIXED is a flexible statistical computer program suitable for fitting individual growth models to data. Its position as an integrated program within the SAS statistical package makes it an ideal choice for empirical researchers seeking to do data reduction, management, and analysis within a single program. Because PROC MIXED was developed from the perspective of a “mixed” statistical model with random and fixed effects, its syntax and programming logic may appear unfamiliar to users who express individual growth models using sets of linked multilevel models. This chapter is written as a step-by-step tutorial that shows how to use PROC MIXED ...