This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book deals with strategies and techniques for identifying, measuring and incorporating non-market values in planning evaluation methodologies. It presents a range of approaches for accomplishing the major purposes of evaluation used in urban and regional planning. The book presents separate methodologies for considering non-market goods, each of which deal with progressively more complex planning situations. It reports on the use of scenarios as an approach to comparing alternatives. The book explores uses of indicators and Strategic Impact Assessment (SIA) that endeavor to deal with greater complexity. It deals with ways of structuring problems that respond to complexity that is so great that model-based approaches fail, where the intention is to assist in fully defining the situation and the options rather than providing numerical scores concerning the most desirable choice.