Abstract
Hierarchical data analyses in different disciplines are reviewed to compare statistical applications of the Hierarchical Linear Model (HLM) software and the SAS MIXED procedure. Similar features of the 2 programs are illustrated through use of the SAS MIXED procedure to confirm an HLM example. The SAS is a standard statistical package with a large group of users; discussions of the shared features in statistical computing may identify options to demystify existing methods for analyzing hierarchical data.