World-Renowned Mathematician Visits Campus

St. Mark’s welcomed Imre Leader, Professor of Pure Mathematics at Trinity College, Cambridge, as this year’s Robert E. Dennard Visiting Scholar. During his visit on September 19-20, 2024, Professor Leader presented to the Upper School and Middle School assemblies and met with students in advanced math and physics classes, the Upper School Math Club, and the Middle School Math Team.

During his presentation to the Upper School, Professor Leader offered a problem nicknamed “Clueless Voting,” which assumes that a group of people will vote on a “yes-no” issue to which there is a correct answer. However, nobody has any idea how to ascertain the correct answer. Intuitively, it seems that however people choose to vote, they only have a 50% chance of getting the correct result. Professor Leader showed that, in fact, with a particular strategy, the majority of the group will vote correctly about 97.5% of the time, despite still being clueless as to the correct answer. He left the Upper Schoolers with a homework question: how can we improve on that 97.5%?  

In the Middle School Assembly, Professor Leader introduced another counter-intuitive problem that he called “Raining in Pittsburgh.”  Assume your favorite baseball team is playing, and statistically, they win a higher percentage of rainy games versus dry games, both at home and away. Should you be happy to hear that rain is starting to fall in the stadium?  It seems obvious that yes, you should be happy they are playing in the rain. However, Professor Leader explained that rain does not necessarily bode well for your team. When you consider the number of rainy versus dry games, your team may be better off in the dry overall. The Middle Schoolers were therefore introduced to Simpson’s paradox, a phenomenon in statistics with implications in computer science, mathematics, social science, and other data-driven fields of study.

A world-renowned mathematician, Professor Leader’s research focuses on combinatorics, in particular extremal combinatorics and Ramsey theory. He won the Junior Whitehead Prize for his contributions to combinatorics and competed for the United Kingdom team in the International Mathematical Olympiad. He remains heavily involved in Olympiad training. Professor Leader is also a noted Othello player, for which he has won numerous national titles. As a strong proponent of math education, Professor Leader challenged Marksmen to stretch their thinking and encouraged their involvement in advanced mathematics, all while demonstrating a joy for teaching.  

Each year, the Robert E. Dennard Visiting Scholars Program brings to campus noted professionals who share their knowledge and experience with the school community. The Program is supported by the Robert E. Dennard Memorial Fund, the D. Gordon Rupe Foundation, and the Margaret McDermott and Ida Green Lectureship Fund. Robert E. Dennard served on the St. Mark’s Board of Trustees from 1964 to 1982.