David Duncan, a distinguished professor of biostatistics at the Johns Hopkins Bloomberg School of Public Health from 1960 to 1984, died June 12, four days before he would have turned 90. During his career, Duncan made many seminal contributions to science and statistics. Duncan’s early work focused on regression analysis, a topic to which he made two important contributions. First, he was an early advocate of what has become known as the Kalman filter, a method for dynamic estimation of the regression equation, which has special application in time series problems. Second, he and co-author Strother Walker discovered logistic regression analysis as early as 1967. Duncan was among the first to advocate the use of logistic regression for binary responses rather than linear regression. Duncan’s career-long love, however, was methodology for dealing with the “multiple comparisons” issue—how to adjust statistical error rates to account for making a large number of inferences from one data set. In 1955, he created the Duncan Multiple Range test, which became the standard tool in the field for two decades. His original paper on the topic is still one of the most cited articles in the medical literature. Later in his career, Duncan adopted a Bayesian approach perspective, creating the k-ratio methodology that is also widely used today. Duncan received his undergraduate training in Australia at the University of Sydney. Following service in the Australian Air Force during World War II, he attended the Iowa State University where he earned his PhD in statistics in 1947. After several years at Virginia Polytechnic Institute and the University of North Carolina, he joined the Department of Biostatistics at Johns Hopkins in 1960. Duncan and his wife Mary Ann retired to Carmel, Calif., in 1984, where Duncan continued his work on multiple comparison problems. He was also an avid tennis player. Duncan regularly communicated with and visited colleagues in the Department of Biostatistics. They remember him as a gentleman and wonderful colleague who served the Hopkins community with distinction for nearly 25 years. In addition to his wife, Duncan is survived by his children, Robert and George Duncan and Margaret Lane, as well as seven grandchildren.
| 
