How and When to Involve Crowds in Scientific Research is a valuable guide to tapping the curious, busy, and creative masses of our species. Across natural sciences, medicine, social science and humanities, scientists and scholars will find this book an inspiring companion for navigating the benefits and challenges of engaging the public across stages of the research process for the collective benefit of all. -- Caren Cooper, North Carolina State University, USA and Citizen Science Theory and Practice The growing involvement of crowds in scientific research represents a significant development in how science is conducted. Poetz and Sauermanns book provides valuable insights into the potential and challenges of crowd participation, effectively combining theoretical frameworks with practical guidance. By systematically addressing key aspects from problem formulation to data analysis and dissemination, the authors offer essential direction for researchers exploring this approach. This book will likely influence both academic discourse and research practice in the years ahead. -- Karim Lakhani, Harvard University, USA How and When to Involve Crowds in Scientific Research is a must-read for anyone interested in scientific innovation in a wide variety of public and industrial sectors. This book helps the policy maker, the researcher, the chief innovation officer, the strategist, and the tactician to determine how to use crowds in a manner that fosters collaborative innovation about complex problems. The authors have managed to create a book that is a how-to guide and primer for practitioners, as well as a scholarly depiction of evidence-based research and directions for future research, particularly for including AI when involving crowds. -- Ann Majchrzak, University of Southern California, USA