This volume examines the proposal that studies of human teaching can be used to inform the design of intelligent computer tutors along with the reciprocal proposal that attempts to understand teachers' knowledge and action can benefit from the models and methods of artificial intelligence and cognitive science. All of the contributors are directly involved in building "Intelligent Tutoring Systems", carrying out empirical studies of teaching to help think about the design of ITSs, taking a cognitive stance in studying teaching, or using Al-based systems to help in teacher education.