This is a book about responsible and evidence-based decision making. It describes how to define policy research questions so that evidence can be applied to them, how to find and synthesize existing evidence, how to generate new evidence if needed, how to make acceptable recommendations that can solve policy problems without negative side effects, how to describe evidence and recommendations in a manner that changes minds. This book is for the community of learners interested in improving the decisions that affect people's lives. Policies are not just the decisions made by a country's rulers or elected officials; policies are also set by corporate executives, managers of department stores, and project leaders in non-profit organizations pursuing environmental protection. In this book, we derive our suggestions from the fundamental belief that evidence-based decision making is superior to decisions based purely on opinion, intuition, and emotion. If we can convince one reader to consider the evidence systematically and responsibly before making a decision, and if we can help one individual to communicate evidence and recommendations in a way that facilitates real change, then this book has achieved the goals we set for ourselves when we sat down to write it.