This document summarizes a lecture on hierarchical linear modeling (HLM). It discusses how to use HLM to determine how much variability in student achievement is attributable to school-level factors versus student-level factors. A toy example is provided to illustrate calculating variance between and within schools. The document also provides an overview of the process for building an HLM model, including determining necessary and significant variables and effects. Information is given about an upcoming basic HLM modeling course in Taipei.