His research focuses on the construction of humanoid robots that interact with people using natural social cues. These robots are used both to evaluate models of how infants acquire social skills and to assist in the diagnosis and quantification of disorders of social development (such as autism). He is an associate editor of the International Journal of Humanoid Robotics and the program chair for the upcoming 6th International Conference on Development and Learning. In 2003, he was awarded an NSF CAREER award.