Theorems in discrepancy theory tell us that it is possible to partition a set of vectors into two sets that look surprisingly similar to each other. In particular, these sets can be much more similar to each other than those produced by a random partition. For many measures of similarity, computer scientists have developed algorithms that produce these partitions efficiently.

A natural application for these algorithms is the design of randomized controlled trials (RCTs). Randomized Controlled Trials are used to test the effectiveness of interventions, like medical treatments and educational innovations.  Randomization is used to ensure that the test and control groups are probably similar.  When we know nothing about the experimental subjects, a random partition into test and control groups is the best choice.

When experimenters have measured quantities about the experimental subjects that they expect could influence a subject's response to a treatment, the experimenters try to ensure that these quantities are evenly distributed between the test and control groups. That is, they want a random partition of low discrepancy.

In this talk, I will survey some fundamental results in discrepancy theory, present a framework for the analysis of RCTs, and summarize results from my joint work with Chris Harshaw, Fredrik Sävje, and Peng Zhang that uses algorithmic discrepancy theory to improve the design of randomized controlled trials.

Bio:   Daniel Alan Spielman is the Sterling Professor of Computer Science, and a Professor of Statistics and Data Science, and of Mathematics at Yale, as well as the James A. Attwood Director of Yale's Institute for Foundations of Data Science.  He received his B.A. in Mathematics and Computer Science from Yale in 1992, and his Ph.D in Applied Mathematics from M.I.T. in 1995.  After spending a year as an NSF Mathematical Sciences Postdoctoral Fellow in the Computer Science Department at U.C. Berkeley, he became a professor in the Applied Mathematics Department at M.I.T. He moved to Yale in 2005.