The role of the devil's advocate is nearly universal in business today. It allows individuals to step outside themselves and raise questions and concerns that effectively kill new projects and ideas, while claiming no personal responsibility. Nothing is more potent in stifling innovation. Over the years, IDEO has developed ten roles people can play in an organization to foster innovation and new ideas while offering an effective counter to naysayers. Among these approaches are the A the person who goes into the field to see how customers use and respond to products, to come up with new innovations; the who mixes and matches ideas, people, and technology to create new ideas that can drive growth; and the , who instantly looks for ways to overcome the limits and challenges to any situation. Filled with engaging stories of how Kraft, Procter and Gamble, Safeway and the Mayo Clinic have incorporated IDEO's thinking to transform the customer experience, is an extraordinary guide to nurturing and sustaining a culture of continuous innovation and renewal.