Drawing on the work of leading scholars, the book comprises a series of studies examining networks among teachers and school leaders, contrasting formal and informal organizational structures, and exploring the mechanisms by which ideas, information, and influence flow from person to person and group to group. The case studies provided in the book reflect a rich variety of approaches and methodologies, showcasing the range and power of this dynamic new mode of analysis. An introductory chapter places social network theory in context and explains the basic tools and concepts, while a concluding chapter points toward new directions in the field. Taken together, they make a powerful statement: that the success or failure of education reform ultimately is not solely the result of technical plans and blueprints, but of the relational ties that support or constrain the pace, depth, and direction of change. This unique volume provides an invaluable introduction to an emerging and increasingly important field of education research.