NOVEMBER 2008 AMSTAT NEWS 5

From ‘Student’ to Student: Reflecting on 100 Years of History … in One Saturday

Yves Chretien, Kari Lock, and Andrew C. Thomas, Harvard University

It was a birthday party like no other: It celebrated the living, the dead, and the immortal. On September 27, we in the

Harvard Statistics Department marked the quinquennial anniversaries of the births of three senior faculty members—Don Rubin (65), Carl Morris (70), and Herman Chernoff (85)—as well as a key paper each of them wrote some number of half-decades ago. This dovetailed nicely with the 100th anniversary of William Gosset’s most cele-brated paper as the pseudonymous Student, giving us another reason to celebrate, not to mention an irresistible theme for jokes and puns.

No one was better equipped to seize this theme than department chair Xiao-Li Meng, who laid out the agenda with a personal photo tribute to each of the honorees and presenters. What struck us most was the personal vulnerability the honorees were willing to expose in order to share the

underlying message that while their work was clearly important to them, it was not enough. A picture of Carl Morris holding his two then-infant daughters was enough to show that to the whole room.

A striking demonstration of how statisti-cal techniques can be used to help people—when well developed and used in an open and transparent manner—was put forth by Fritz Scheuren. In his tribute to Don Rubin and his work on multiple imputation, Scheuren demonstrated a recent and highly relevant example: estimating an amount of collected money held in trust for Native Americans since 1887. Scheuren illustrated the difficulties involved in putting together a reliable estimate of past accountings when there was a substantial amount of missing data to be reckoned with. Measuring the uncertainty when imputing for missing data was the problem Scheuren asked Rubin to tackle, admittedly in another context 30

years earlier. The original problem inspired Rubin’s multiple imputation approach, which has been widely used since.

We of the personal computer generation have witnessed an ever-increasing quantity and complexity of data available in vari-ous fields, but we’ve also been spoiled with computers that can handle it, often with a minimum of direction. It was illuminating to see Andrew Gelman examine how Carl Morris’ work on parametric empirical Bayes helped a previous generation of statisticians deal with multilevel data (by showing the value of shrinkage estimation for inference about a set of unknown quantities) and still incorporate important and fresh ideas for thinking about multilevel modeling. In particular, the comparison of parametric empirical Bayes methods with fully Bayesian methods highlighted the advantages of mul-tilevel modeling, as Gelman offered his own insights on how and when to pool data, based in part on Morris’ ideas.

With the advent of cheap computing, graphics have greatly reduced in price and increased in ease of creation, which has spurred a quest to generate more mean-ingful forms of visualization. Herman Chernoff, however, had insights ahead of his time, as he published the visualization

From left: Speakers and honorees include Stephen Stigler, Fritz Scheuren, Steve Wang, Herman Chernoff, Don Rubin, Carl Morris, Andrew Gelman, and Xiao-Li Meng. Rubin, Morris, and Meng are wearing their newly acquired Bayes ties, a gift from presenter Stigler. Meng is wearing a Singapore-made “celebration shirt,” a gift from a department alumnus.

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6 AMSTAT NEWS NOVEMBER 2008

technique of Chernoff faces 35 years ago. Steven Wang demonstrated by several appli-cations the benefits of representing multi-variate observations as facial expressions, a context known to be handled well by the human brain. It’s a unique and very cute (in Chernoff ’s words) way to simultaneously view multiple dimensions. Wang also pre-miered, with the assistance of Photoshop, his updated version using actual human faces and another ‘cute’ version with animal characters, Chernoff pigs.

The ‘birthday boys’ having been hon-ored, Stephen Stigler took to the podium to deliver his tribute for the 100th birthday of the underlying form of the t-distribution. Stigler outlined the publication for the audience, explaining Gosset’s motivations, his methods, what he achieved, and what he left for others after him. As for what would make the Student name famous and espe-cially historically notable, Stigler showed how Gosset’s work fit into a unique histori-cal context by showing its influence on the work and personalities of R. A. Fisher and Karl Pearson. Gosset was one of the few people able to get along professionally and personally with both giants.

A presentation by graduate students rounded out the Quintessential Celebration. In the session “From Student to students,” Harvard PhD students Paul Baines, Yves Chretien, and Kari Lock attempted, with some success, to stump the crowd with trivia about the birthday boys. The three were interviewed prior to the event, and question by question their responses were presented—without identification—to the audience. The audience was then chal-lenged to match their longtime colleagues to the responses given. Their audience’s guesses were generally accurate, although there were some exceptions. The audience unanimously agreed that “a psycholo-gist” must have come from Rubin, whose undergraduate degree was in psychology, in response to the question, “What would you be right now if you had not become a statistician?” Much to everyone’s surprise, this was actually Morris’ answer. Rubin had responded “a retired race car driver.”

After the final session, Meng and PhD student Andrew Thomas offered closing remarks as a bridge to the evening’s fes-tivities, a “Student t Party” at Harvard’s Cambridge Queen’s Head pub. In tribute to Gosset’s lifelong employer, participants were offered Guinness, as well as selections from the Boston-based Harpoon Brewery.

A veteran quizmaster, Thomas presided over a challenging game of bar trivia, with special emphasis on questions concerning statistics and Guinness beer. Points were awarded to teams using the probability scoring technique, a method Morris uses in his introductory classes. A team headed by guest speaker and trivia buff Wang took home first prize.

Quintessential Contributions was suc-cessful in honoring three landmark achieve-ments by three eminent Harvard statisti-cians. By setting these accomplishments within a historical context and illustrating the subsequent development of these ideas, the speakers revealed the connection of past innovations with current practice. Each generation of statisticians makes its contri-bution after being a student of the previous generation; how fitting, then, that excel-lence in our discipline was honored with a tribute to the original Student. For more about Quintessential Contributions, visit http://stat.harvard.edu. n

The Honored PapersDonald B. Rubin. “Multiple Imputations in Sample Surveys—A Phenomenological Bayesian Approach to Nonresponse.” In ASA Proceedings, Section on Survey Research Methods, ASA, 1978

Carl N. Morris. “Parametric Empirical Bayes Inference: Theory and Applications.” JASA, 1983

Herman Chernoff. “The Use of Faces to Represent Points in K-Dimensional Space Graphically.” JASA, 1973

Student. “The Probable Error of a Mean.” Biometrika, 1908

CorrectionThe person in the photo on Page 31 of the September issue is Jeff Thompson, not Roger Woodard. We regret the error.

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