Ruth Anne Rehfeldt, PhD, is professor of behaviour analysis and therapy at Southern Illinois University, Carbondale.She holds doctoral and master's degrees in psychology from the University of Nevada and a bachelor's degree inpsychology from the University of Puget Sound. She is also a board-certified behaviour analyst.Jonathan Tarbox, PhD, is program director of the Master of Science in Applied Behaviour Analysis program at theUniversity of Southern California, as well as director of research at FirstSteps for Kids. Tarbox is the incoming editor ofthe journal Behaviour Analysis in Practice and serves on the editorial boards of five major scientific journals related toautism and behaviour analysis. He has published four books on autism treatment and well over 70 peer-reviewed journalarticles and chapters in scientific texts. His research focuses on behavioural interventions for teaching complex skills toindividuals with autism, treatment of feeding disorders and technology in autism treatment. He is a frequent presenter atautism and ABA conferences worldwide and a regular guest on television and radio.Mitch Fryling, PhD, is associate professor in the applied behaviour analysis programs at California State University, LosAngeles. He has authored and coauthored several scholarly publications, primarily in the area of behavioural theory andphilosophy, especially as it pertains to complex human behaviour and system development in behaviour analysis. Fryling has also served as a reviewer, editorial board member and associate editor for various behavioural journals and is theincoming editor of The Psychological Record.Linda J. Hayes, PhD, is Distinguished International Professor at the University of Nevada, Reno. There she co-founded the behaviour analysis program in the department of psychology and served as its director for more than a decade. She founded and directs the department's Satellite Programs in Behaviour Analysis. Hayes is a fellow of the Association for Behaviour Analysis International and has served two terms as its president. She is best known for her work in behaviour theory and philosophy.