William B. Stiles is Professor Emeritus of Psychology, Miami University, Oxford, Ohio, USA. He has also taught at the University of North Carolina at Chapel Hill, and he has held visiting positions at the Universities of Sheffield and Leeds in the United Kingdom, at Massey University in New Zealand, and at the University of Joensuu in Finland. He received his Ph.D. from UCLA in 1972. He is President-Elect of Division 29 (Psychotherapy) of the American Psychological Association and a Past President of the Society for Psychotherapy Research. He has served as Editor of Psychotherapy Research and is currently Editor of Person-Centered and Experiential Psychotherapies and Associate Editor of British Journal of Clinical Psychology. He has published over 250 journal articles and book chapters, most dealing with psychotherapy theory, research, and practice, verbal interaction, and research methods.