By Louis DiPietro
On

 

Christopher Jennison, Ph.D. ’82, whose research on and refinement of sequential testing methods has made clinical trials more efficient, has been named the 2025 recipient of the Department of Statistics and Data Science’s annual Distinguished Alumni Award. 

Jennison, professor of statistics at the University of Bath in the United Kingdom, will be honored at the department’s Eighth Celebration of Statistics and Data Science on Friday, Sept. 5 in the J. Willard Marriott Executive Education Center in the Statler Hotel. He will also give the keynote presentation as part of the day-long conference, which features talks from eight other statistics luminaries. Cornell scholars are invited to attend, though seats are limited and available on a first-come, first-served basis. Registration is required.


“It’s a real honor to be in the company of past award recipients like Larry Brown [Ph.D. ‘64], Grace Wahba [‘56], Jim Berger [Ph.D. ‘74], and Iain Johnston [Ph.D. ‘81],” Jennison said. “I feel very flattered.”


Jennison’s work and development of statistical methods in clinical trials spans more than 40 years, starting with his doctoral thesis from his days at Cornell. The paper, “Repeated Confidence Intervals for Group Sequential Clinical Trials,” published in 1984, with coauthor and Cornell advisor, Bruce Turnbull, Ph.D. ‘71, professor emeritus in the Department of Statistics and Data Science, the School of Operations Research and Information Engineering (ORIE), and Cornell Engineering, pitched novel statistical methods that could be used to more flexibly monitor clinical trials comparing two or more treatments. Put simply, the methods could show the effectiveness or otherwise of a new treatment earlier in the process and signal to researchers when to stop the trial to declare efficacy or to stop for futility, thus saving time and money. 

Jennison has been refining this work ever since, and today, his methods have helped shape the standard for how clinical trials are statistically monitored. The book he and Turnbull published in 1999 – “Group Sequential Methods with Applications to Clinical Trials” – has become a quintessential textbook for practicing statisticians. A second, much expanded edition is forthcoming. 

Raised in Hull, in the U.K., Jennison earned a bachelor’s in mathematics and a diploma – similar to a master’s – in statistics from Cambridge University in 1978. Charmed by a past summer job in Cape Cod, Jennison chose to pursue his doctoral studies in statistics in the U.S. He wrote to Jack Kiefer at Cornell, and got an offer. 

“Where I grew up was a bit insular, so coming to the States, there was this whole array of international students, all kinds of different people, all kinds of fascinating views of life,” he said. “What a great environment.”

Christopher Jennison, Ph.D. ’82

“Most of my career was unplanned. My message to graduate students is: take what happens, and look out for opportunities.”

His next four years in Ithaca would be spent gleaning insights from some of Cornell’s mathematical and statistical heavyweights of the day: Larry Brown, Bob Bechhofer, Roger Farrell, Jiun Hwang, Tom Santner, Les Trotter, and Phil McCarthy, to name a few. 

“It was quite a set of mentors,” he said. 

Chief among them was Turnbull, then a professor in ORIE and the graduate field of statistics, a precursor to the Department of Statistics and Data Science. The pair would form an enduring friendship and professional partnership that continues today. Together, “Jennison, C.” and “Turnbull, B.W” have coauthored dozens of papers over the years, and both are now Distinguished Alumni Award recipients. Turnbull received the honor in 2016. 

“We just clicked,” Jennison said of his friendship and professional partnership with Turnbull. “We had things in common: both English; a shared sense of humor, and an interest in applied statistics with a strong mathematical base.”

“I feel privileged to have interacted with Chris as a coauthor and a friend over these many years,” Turnbull said. “It is gratifying to know that our joint work has had an impact on the design, monitoring, and interpretation of results of clinical trials both in the U.S. and internationally.”

After completing his Ph.D., Jennison returned to the U.K. and served as a lecturer in statistics at the University of Durham for three years. In 1985, he joined the faculty in the Department of Mathematical Sciences at the University of Bath, where he has remained. A professor of statistics, Jennison has also served as the department’s head – twice, from 2000 to 2003 and again for a short spell in 2015 – and as the dean of science from 2004 to 2010. He has been associate editor of numerous statistics publications and has served as secretary and chair of the Royal Statistical Society Research Section Committee. His awards and honors include the Guy Medal in Bronze from the Royal Statistical Society in 1992. 

“Throughout my career, I just fell on my feet,” Jennison said. “Most of my career was unplanned. My message to graduate students is: take what happens, and look out for opportunities.”

Louis DiPietro is a writer for the Cornell Ann S. Bowers College of Computing and Information Science.