He received a A.B. in Philosophy from Harvard University, and a Ph.D. in Computer Science from the University of Massachusetts at Amherst in 1998. His PhD dissertation introduced a policy iteration algorithm for POMDPs that represents policies as finite-state controllers, and he has published several methods for scaling up algorithms for solving POMDPs. Other research interests include heuristic search and use of model-checking techniques in search and planning. He received an NSF Career Award in 2000.