Introductory Guide to HLM With HLM 7 Software

H LM software has been one of the leading statistical packages for hierarchical linear modeling due to the pioneering work of Stephen Raudenbush and Anthony Bryk, who created the software and authored the leading text on hierarchical linear and nonlinear modeling (Bryk & Raudenbush, 1992; Raudenbush & Bryk, 2002). Though differences among software packages’ capabilities have diminished over time, HLM 7 offers a number of appealing advantages and capabilities. Among these are what many consider to be a more intuitive model specification environment, greater ease in creating threeand four-level models, its wide choice of estimation options, integrated likelihood ratio hypothesis testing, graphics options, and the ability easily to handle heterogeneous hierarchical linear models (where the dependent is thought to have different error variances for different levels of some grouping variable such as Agency).