Volume 2 of Bold Ventures provides detailed insights about five notable U.S. innovations in science education. The first study examines California’s ground-breaking curriculum framework, progressive statewide assessments and, particularly, opportunities for professional development of teachers. The second case looks at project 2061’s seminal publications and, especially, the processes used to develop them. Studies of Kids Network and Voyage of the Mimi illuminate what these innovations look like in elementary and middle school classrooms and discuss key adoption and implementation issues. A study of Chemistry in the Community particularly emphasises instructive dimensions of its development and the intended and unintended ways this course is being used in high school curricula. These cases, along with the Volume 3 studies of three mathematics innovations, comprise the United States participation in the largest cross-national case study project ever undertaken. Volume 1 reveals patterns among all eight innovations.