Siegfried Greif, Dr. phil., retired as Professor and Chair of Work and Organizational Psychology, the University of Osnabrück, Germany. His current work and research focus are on expanding and improving the effectiveness of coaching methods. He has published 20 books, including monographs on Coaching und ergebnisorientierte Selbstreflexion (2008, Hogrefe) and Was ist Coaching? (2021), and was co-editor of the International Handbook of Evidence-Based Coaching, 2022, Springer). He is the author of many articles in internationally recognized journals and of various book chapters. He conducts science-based and certified coaching training for practitioners in a project run by Prof. Dr. Rudolf Kerschreiter, Chair of the Division of Social, Organizational and Economic Psychology, at the Free University of Berlin, together with the association Arbeit, Bildung und Forschung e.V. Professor Greif is a member of the German Psychological Society and founder of the Innovation Award of the Division of Work, Organizational and Business Psychology as well as a member of the German Federal Association of Coaching (DBVC, Senior Coach) and the International Society of Coaching Psychology (ISCP). He was a Research Fellow of the British Psychological Society (1984), held the Wilhelm Wundt Chair at the University of Leipzig (1991/92), and has been a member of the Scientific Advisory Board of the Research Council of the Institute of Coaching (IoC) at the Harvard Medical School, USA, since 2016.