A high-energy particle theorist, Professor Stelzer has concentrated on standard model physics as hadron colliders. Professor Stelzer is a member of the Physics Education Group at the University of Illinois, where he has led the development and implementation of tools for assessing the effectiveness of educational innovations in introductory courses and expanding the use of web technology in physics pedagogy. He was instrumental in the development of the iClicker™ and is a regular on the University’s "Incomplete List of Teachers Ranked as Excellent by Their Students".