Usable knowledge for learning from mistakes is hard to come by. However, planning for iteration may lead to failures that are "small scale and early, rather than late and large." Part I of this book uses a number of stories to introduce a data-driven approach to learning from failure. Parts II and III serve as a field guide for reflecting on a current project or planning for an upcoming initiative. It was written by Anjali Sastry, from the MIT Sloan School of Management, and Kara Penn is from Mission Spark, a social enterprise consultancy.