Dr. Stahl is trained in computer science, artificial intelligence, social philosophy, cognitive science and learning science. Since 2002, he has taught human-computer interaction (HCI), computer-supported collaborative learning (CSCL), computer-supported cooperative work (CSCW) and social informatics (SI) at Drexel’s iSchool. He directs a multi-million dollar research project in online collaborative math in conjunction with the Math Forum and international colleagues. His research approach includes theory building, system development and empirical studies of software usage. He has developed software systems and prototypes to explore support for collaborative learning, design rationale, perspectives and negotiation. His theory combines various sources from philosophy, education, sociology, communication and anthropology. He has developed a methodology of fine-grained empirical investigation into how groups of people learn to use artifacts like groupware systems in real-world settings such as school classrooms and virtual math teams. Dr. Stahl is a world-class researcher in CSCL, having organized international conferences, founded an international journal, published a volume on Group Cognition in MIT Press and one on Studying VIrtual Math Teams in Springer Press and written over 150 professional papers. His website and blog are major resources for the CSCL research community.