Improvement in Action, Anthony S. Bryk's sequel to Learning to Improve, illustrates how educators have effectively applied the six core principles of continuous improvement in practice. The book highlights relevant examples of rigorous, high-quality improvement work in districts, schools, and professional development networks across the country. The organizations featured in the book have addressed, with remarkable results, long-standing inequitable educational outcomes in high school graduation rates, college readiness, and absenteeism. The cases emphasize the measures the educators took and the thinking that motivated their actions. Bryk describes how improvers, working in different contexts and confronting different problems, used select principles, tools, and methods to make improvement come to life. Brief analytic reflections are embedded throughout the narratives, and each chapter concludes with an analysis of a set of larger lessons illuminated by the organization's story. Taken as a set, these examples offer readers valuable insights about the actual dynamics of doing improvement work. Improvement in Action, paired with Learning to Improve, provides readers with a comprehensive understanding of the practice, method, and theory of large-scale continuous improvement in education.