This Open Access book provides detailed practical guidance on how to do a Delphi study to establish a consensus across the broad range of social, psychological, health and environmental sciences. The book informs the design of Delphi studies by drawing on wisdom-of-crowds research on the conditions under which groups make better-quality judgements. It covers the development of the Delphi method and its many variations, as well as the ways this method has been used to make judgements of facts where the evidence is imperfect, set methodological standards, make predictions, define foundational concepts, determine collective values, and improve professional practice and policy. It takes the reader through the steps in carrying out a Delphi study and the choices that have to be made at each step. It also covers the implementation of Delphi findings in practice. Case examples are included throughout drawing from a variety of disciplines.
