Persi Diaconis is Professor of Mathematics and Statistics at Stanford University. He works in the mathematics and practice of Bayesian statistics (conjugacy, consistency properties of Dirichlet priors, deFinetti's theorem). In rates of convergence for Markov chains to stationality (how many times to shuffle cards, understanding the Metropolis algorithm, geometric theory of Markov chains). He also works in combinatorics, group theory, and random matrix theory and in the philosophy of probability.