His research interests are in human-computer interaction, artificial intelligence and applied machine learning. The phrase "intelligent interactive systems" describes well many of his interests: He is interested in how intelligent technologies can enable novel ways of interacting with computation, and in the new challenges that human abilities, limitations and preferences create for machine learning algorithms embedded in interactive systems. Together with several students, he has started the Intelligent Interactive Systems Group at Harvard. The main themes in his current research are ability-based user interfaces, creativity support tools, and interactive machine learning.