This chapter sets out the methodology of the approach to behavioral economics developed in this book, emphasizing its rejection of the static “as if” approach of conventional economics and the latter’s view of rationality. It introduced the idea of a decision cycle (problem recognition, search, evaluation, choice, implementation and hindsight review), while emphasizing that how decisions are taken depends on their context. This leads to a pluralistic analysis where alternative perspectives share the idea that everything we do is based upon systems of operating rules and routines. The chapter explores the research methods of behavioral economics, including the roles of anecdotes, introspection, textual sources, questionnaires, experiments and computer simulations. Before closing by outlining the rest of the book, it introduces the evolutionary economics and evolutionary psychology perspectives that are closely related to the pre-1980 approaches to behavioral economics and kept building upon them after 1980 when behavioral economics was refashioned by Thaler with a focus on “heuristics and biases” that took the conventional approach to economic rationality as its reference point.