David Beatty Duncan who died at the age of 89 at his home in Carmel Valley Ranch, Oregon USA on June 12th this year, was an Australian-born statistician who won world-wide academic acclaim.

David was born the year his eldest brother was killed in France. When David was 13, his father died. The family was not well off and they struggled through the Depression. As soon as they were able, the older children sought employment and were thus unable to avail themselves of educational opportunities. However as they became established in their respective careers they contributed to ensure that David’s academic potential was developed.

He studied at Sydney Boys High School, where he was a hard working and diligent student. His academic results, particularly in the sciences, were quite outstanding. His strengths were Physics and Mathematics. After High School, he enrolled in Agricultural Science at Sydney University, graduating in 1937. He then became a teacher at a Parramatta high school until the start of World War II. During this time he undertook further studies in mathematics.

He joined the AIF in 1939 where he was a member of the Sound Ranging Unit. A family anecdote relates to him studying the instructions in the military manual for setting the guns for long range fire and identifying an error in the mathematics. He drew this to the attention of his superior officers. Just prior to his unit’s departure for North Africa, the value of his mathematical skills was recognised and he was transferred to the RAAF, initially as an instructor in navigation for flight crews. He was later stationed in Melbourne assessing the effectiveness of pilot training methods. By the end of the war he had risen to the rank of Squadron Leader.

On his discharge he was awarded a Pawlett Fellowship, a traveling scholarship for Agriculture graduates to undertake further studies. He elected to pursue a Ph.D. in Agricultural Statistics at Iowa State University, Ames, Iowa. His supervisor was the famed Professor George Snedicor. He met, wooed and, on his second proposal of marriage, won the hand of Mary Ann Kohli, a beginning instructor in the Physical Education Department.

David returned to Sydney in 1947, lecturing in Biometrics in the Faculty of Agriculture at Sydney University. Mary Ann joined David shortly after his return and they were married later that year. Their first son Robert Ames was born in Sydney.

David lectured at Sydney University for 4 years His students were always very aware of the thought he gave to the structure of his course and the thoroughness of his presentations. He succeeded in passing on to many of his students a lifelong fascination with the philosophic and practical aspects of planning experimental procedures and analyzing the results.

In 1951 David and Mary Ann returned to her native land. For the next 5 years David was a Faculty Member in the Statistics Department of the Virginia Polytechnic Institute. In 1956-1957 he was a Research Faculty member in Agronomy at the University of Florida, then from 1957 to 1962, Faculty member in Statistics at the University of North Carolina. This was followed by an appointment in Biostatistics at the Johns Hopkins University, Baltimore, Md., from where he retired in 1983. He had many successful students who have kept in touch with him and valued his excellence as a teacher and a mentor.

In a paper published in 1955, he set out new procedures which came to be known as “The Duncan Multiple Range and Multiple F Tests”. This was a new way for deciding if any real differences could be inferred from the observed differences between treatments in an experiment.

In his retirement in Carmel CA., David was honoured as an Emeritus Professor of Statistics, courtesy of the Faculty in Statistics at Oregon State University.

David is survived by his wife Mary Ann, two sons, a daughter and seven grandchildren.



Written by Malcolm McDonald and Bob Duncan