The multilevel model and SAS programs

The growth curve analysis is a hotspot in the analysis to understand the characteristics of things change over time. However, the conventional curve fitting method does not apply to the structure data obtained by repeated measurement. Although the outline design matrix computation can be used to treat the structure data in the growth curve analysis, the corresponding SAS programs are very long and hard to understand. In this paper, we present algorithms for multi-level model applied to the analysis of the growth curve. The usage of the algorithms is demonstrated by practical examples. The very simple and clear SAS programs for the presented method are also given.