Hierarchical Linear Modeling (HLM): An Introduction to Key Concepts within Cross-Sectional and Growth Modeling Frameworks. Technical Report #1308.

This manuscript provides an overview of hierarchical linear modeling (HLM), as part of a series of papers covering topics relevant to consumers of educational research. HLM is tremendously flexible, allowing researchers to specify relations across multiple “levels” of the educational system (e.g., students, classrooms, schools, etc.). The manuscript contains three chapters. In Chapter 1, the concept of HLM is introduced, as well as topics that will be covered in the paper. Chapter 2 provides a basic overview of cross-sectional HLM models, complete with an illustrated example contrasting results of an HLM model with a standard single-level regression model. The bulk of the manuscript is reserved for Chapter 3, which covers the application of HLM to modeling growth. Chapter 3, again, concludes with illustrated examples. The manuscript is concluded with an overall discussion of HLM and what was and was not covered within the