The book introduces a model for the innovation process helping inventors, investors, and entrepreneurs to understand the nature of opportunities and risks on the path to success. The authors analyze several landmark innovations in detail, revealing surprising and essential elements common to all of them. They give readers specific tools for quickly identifying essential present and missing elements of high value problems and proposed solutions, resulting in an accelerated innovation development and evaluation cycle. This material is the basis for courses at Stanford and the University of Michigan and will be adopted where these courses are taught.