Dennis C. Turk, PhD, is the John and Emma Bonica Professor of Anesthesiology and Pain Research and Director of the Center for Pain Research on Impact, Measurement, and Effectiveness at the University of Washington School of Medicine. He is Editor-in-Chief of the Clinical Journal of Pain and a past president of the American Pain Society. Dr. Turk's research focuses on assessment and treatment of patients with a range of chronic pain conditions, coping with and adaptation to chronic illness, clinical decision making, and clinical trial methodology. Widely published, Dr. Turk is the recipient of honors including the John C. Liebeskind Award for Career Contribution to Pain Research from the American Academy of Pain Management and the Wilbert E. Fordyce Clinical Investigator Award and the John and Emma Bonica Public Service Award, both from the American Pain Society. Robert J. Gatchel, PhD, ABPP, is Distinguished Professor of Psychology and Nancy P. and John G. Penson Endowed Professor of Clinical Health Psychology at The University of Texas at Arlington, where he is also Director of the Center of Excellence for the Study of Health and Chronic Illnesses. In addition, he is Clinical Professor at the Eugene McDermott Center for Pain Management at The University of Texas Southwestern Medical Center at Dallas. Dr. Gatchel's research and clinical work have focused on the biopsychosocial approach to the etiology, assessment, treatment, and prevention of chronic stress and pain behavior; the comorbidity of physical and mental health disorders; and clinical health psychology. Widely published, Dr. Gatchel is the recipient of honors including the Senior Scientist Award from the National Institutes of Health and the Gold Medal Award for Life Achievement in the Application of Psychology from the American Psychological Foundation.