Frances K. McSweeney is Regents Professor and Vice Provost for Faculty Affairs at Washington State University, USA. Cited as one of the most prolific contributors to behaviour analysis journals, she holds both Masters and Ph.D. degrees from Harvard University. The former Chair of WSU’s Department of Psychology and of the Association for Behavior Analysis International (ABAI). Professor McSweeney is a fellow of ABAI, of the American Psychological Association (Divisions 3 and 25), and of the Association for Psychological Science. Her recent research focuses on short-term changes in reinforcer effectiveness. 

Eric S. Murphy is Associate Professor in the Department of Psychology at the University of Alaska Anchorage, USA, and holds a doctorate in experimental psychology from Washington State University. He has published research in the Journal of the Experimental Analysis of Behavior and Journal of Applied Behavior Analysis, and in 2010 received UAA’s Faculty Exemplar Award for enhancing undergraduate research opportunities. A specialist teacher and researcher in behavior analysis, Dr Murphy is currently leading a study of the variables regulating reinforcer effectiveness.