Matriculating at Hobart because of "its noteworthy chemistry department," he pursued a war-time pre-medical program for three years and then transferred to the University of Rochester School of Medicine in 1943. At Hobart, he was a member of the Kappa Sigma fraternity, played in intramural sports, and was elected to Epsilon Pi Sigma, the honorary scientific society in recognition of his undergraduate scientific achievements. He graduated from the University of Rochester with the M.D. degree in March, 1946. He then served as a research associate at the Cornell Medical School in New York, N.Y., for two years before joining the U.S. Public Health Service in Bethesda, Md. From 1948 until 1966, he was head secretary in the energy metabolism lab, physiology department/National Cancer Institute, National Institutes of Health (Bethesda, Md.). Dr. Pratt has had published numerous articles in the biomathematical aspects of spectroscopy, human physiology, and the effect of tumor growth on experimental animals. In 1966, he became the first director of the Division of Computer Research and Technology at the National Institutes of Health, one of the major NIH divisions. He retired in 1992. Dr. Pratt is a recognized leader on the computer's use in biomedical research and methods of information in medicine. He has done pioneering work in the areas of mathematical linguistics and computational linguistics, as applied to the computer-based processing of natural language data for communication in medicine. His professional memberships include the Association for Computer Machinery, American Association for the Advancement of Science, and, as a Fellow, American College of Medical Information. He has been honored by the Department of Health, Education, and Welfare and also received an honorary Doctor of Science degree from the Colleges in June, 1973.