As online professional development courses for teachers have grown, the discussion forum has become a locus of considerable research. This study analyzes the discussion forums in four different sessions of a short (4-week) online course for teachers from six schools in three states. This study also compares four methodologies, all of which have a visualization component: an analysis of data from the CMS; network analysis; content analysis; and sequential analysis. In addition, this study describes the insights into the effectiveness of the course design and facilitation that each approach provides, correlates these with participant satisfaction, and argues for using a combination of methods when studying discussion forums in online courses.