Gary Klein, PhD., is Chairman and Chief Scientist of Klein Associates. He has developed models of how people actually make decisions; detect and solve problems; develop and modify plans in a wide variety of domains, including firefighting, aviation, command and control, shopping for products, and software troubleshooting; and under conditions such as uncertainty and time pressure. He has also described team coordination and team adap-tation. Dr. Klein and his colleagues have applied a decision-centered approach to system design and training programs. He has edited three books on naturalistic decision making and authored Sources of Power: How people make decisions (1998, MIT Press). He received his PhD. in Experimental Psychology from the University of Pittsburgh in 1969, spent several years as an Assistant Professor of Psychology at Oakland University, Rochester, Michigan, and worked as a Research Psychologist for the Air Force from 19741978. He founded Klein Associates in 978 in order to study a range of topics that are now described as the Naturalistic Decision Making framework.