James O. Prochaska, Ph.D., is a Professor of Psychology and Director of the Cancer Prevention Research center at the University of Rhode Island.John C. Norcross, Ph.D., is Professor and former Chair of Psychology at the University of Scranton.Carlo C. DiClemente, Ph.D., is Professor and Chair of the Department of Psychology at the University of Maryland, Baltimore County.Their model for self-change has attracted attention worldwide and has been applied in programs sponsored by such organizations as the national cancer Institute and the National Institute of Drug Abuse.