This is a book about making choices based on the evaluation of alternatives. Primarily written for people having to learn to make policy decisions, the methods discussed are generally applicable. The starting point of the book is the notion that the outcomes of choices are often worse than people expect. To improve outcomes, an evaluation beforehand and a thorough deliberation of the advantages of various alternatives can be useful. This book discusses the major problems and makes recommendations for decision makers who want to optimize the outcomes of their choices.