Robert Osher Schlaifer (13 September 1914 – 24 July 1994) was a pioneer of Bayesian decision theory. At the time of his death he was William Ziegler Professor of Business Administration Emeritus of the Harvard Business School. In 1961 he was elected as a Fellow of the American Statistical Association. Biography The son of Osher Schlaifer (who was later the superintendent of schools in Dundee, Illinois), a native of Vermillion, S.D., and a graduate of Amherst College, Schlaifer had a unique background for a statistical decision theorist. He was trained as a classical historian and classical Greek scholar: he attended the American School of Classical Studies in Athens and earned a Ph.D. in ancient history at Harvard in 1940. He taught history, economics and physics at the Faculty of Arts and Sciences at Harvard. During the Second World War he started writing technical reports and produced a major volume on the development of aircraft engines. He got an appointment at the Harvard Business School and when the statistics teacher retired he started to teach statistics—starting by teaching himself. He had very little mathematical background and Raiffa recalled how they worked together: "I would teach him something about linear algebra in the morning and he would show me how it could be applied in the afternoon." (from the interview with Fienberg) Schlaifer made an important contribution to Bayesian decision theory. His work and his character are described in the following appreciations. In 1992 the Decision Analysis Society awarded Schlaifer the Frank P. Ramsey Medal for distinguished contributions to the field of decision analysis. In making the award Bob Winkler noted Schlaifer's pioneering efforts in decision analysis. His 1959 book, Probability and Statistics for Business Decisions, was a landmark effort, coming only five years after L. J. Savage, in his classic Foundations of Statistics, presented a development of subjective probability and utility but then inexplicably reverted to minimax arguments in the latter part of the book. Schlaifer, with no formal training in statistics or mathematical modeling, got it right and took the first steps toward bridging the theory/practice gap. Winkler also quoted the following assessment from Howard Raiffa, who worked with Schlaifer and was the recipient of the first Ramsey Medal in 1984: “The basic ideas of statistical decision theory were conceived by (Schlaifer) independently of the work of L. J. Savage or de Finetti, and early on he saw that those