Donald (Don) F. Morrison passed away peacefully on July 11, 2022 at the age of 91. He was a professor in the Department of Statistics in the Wharton School at the University of Pennsylvania from 1963 until his retirement in 1999. Prior to Penn, Don worked in research positions at MIT Lincoln Laboratory, the National Institutes of Health, and Bell Labs. 

Don was born in Stoneham, Massachusetts, on February 10, 1931. He received an M.S. in statistics from the University of North Carolina, Chapel Hill in 1957, and a PhD in Statistics from Virginia Tech in 1960, where his dissertation adviser was Herbert A. David. Don became a Fellow of the American Statistical Association in 1968, and an IMS Fellow in 1975.

Don wrote two widely used texts. Multivariate Statistical Methods was originally published in 1967, and a fourth edition appeared in 2005. Applied Linear Statistical Methods was published in 1983. Many graduate students were trained in multivariate analysis by virtue of using his book. In a lucid fashion, he was able to allow the reader to focus foremost on ideas, and less so on detailed computations. Don most loved his time with students in the classroom, and this inspired him to write the two texts. 

Don wrote seminal papers that developed new methodologies in multivariate analysis, motivated by data structures that arise in practical settings. He developed tests for the equality of the elements of the multivariate normal distribution under certain relevant covariance structures. In studying optimal spacing of repeated measurement designs, he determined optimal times to take measurements so that the resulting test of equality of treatment effects has maximum power. In other work, he proved that simple, partial, and multiple correlations follow the Wishart distribution with non-centrality parameters affected by intra-class correlations.

Don chaired the Wharton Department of Statistics from 1978 to 1985. During his tenure there were important hires that began the process of transforming the department into research prominence. He was instrumental in convincing the Wharton School administration to reduce faculty teaching loads so that the department could be competitive with top tier departments in hiring faculty. In addition to his service to the department, he was editor of The American Statistician from 1972 to 1975, and an associate editor of Biometrics. After retirement, Don served as secretary to the Wharton School faculty for 15 years.

Don was beloved by his PhD students, and several of them endowed the Don Morrison PhD Research Fund in his honor. The fund has provided resources for doctoral students to attend conferences.

Don was an amateur railroad historian his entire life, with a special interest in signaling systems. He collected historic books, documents, and signal equipment, and he created model railroads with his family. He contributed actively to the Boston & Maine Railroad Historical Society and the Norfolk & Western Historical Society. After retiring, he volunteered from 2001 to 2011 as a trainman at the Wilmington and Western Railroad. While an undergraduate, Don worked manual labor installing railroad underground cable. It was a gritty, dirty job that helped shape his views on how he treated others, and, as his son Norman remarked, it contributed to his tenacity. Norman also commented, “Growing up, it was all about the trains. We never flew on a plane. We took trains across the country. We took trains to Canada. Everything was a train or a car.”

Students and colleagues remember Don as very kind and patient. He could be quiet, but he loved a good joke and often broke into loud laughter while relating a funny story or anecdote. He was highly respected across the Wharton School faculty for his intellectual capabilities and his integrity.

Don is survived by his wife of 54 years, Phyllis, sons Norman and Stephen and their wives, three grandchildren, and a sister.

Written by Abba Krieger and Paul Shaman, both at the University of Pennsylvania. Some of the details are taken from a remembrance posted on the Wharton School’s website, and from an obituary written by the family.