One of the great challenges now facing education reformers in the United States is how to devise a consistent and intelligent framework for instruction that will work across the nation's notoriously fragmented and politically conflicted school systems. Various programs have tried to do that, but only a few have succeeded. Improvement by Design looks at three different programs, seeking to understand why two of them - America's Choice and Success for All - worked, and why the third-Accelerated Schools Project - did not. The authors identify four critical puzzles that the successful programs were able to solve: design, implementation, improvement, and sustainability. Pinpointing the specific solutions that clearly improved instruction, they identify the key elements that all successful reform programs share. Offering urgently needed guidance for state and local school systems as they attempt to respond to future reform proposals, Improvement by Design gets America one step closer to truly successful education systems.