Steve Ritter is Founder and Chief Scientist at Carnegie Learning. He has been developing, analyzing and evaluating educational technology for over 20 years. He earned his Ph.D. in Cognitive Psychology at Carnegie Mellon University and was instrumental in the development and evaluation of the Cognitive Tutors for mathematics. He is the author of numerous papers on the design, architecture and evaluation of Intelligent Tutoring Systems and other advanced educational technology. He currently leads the research team at Carnegie Learning, focusing on improving the educational effectiveness of its products and services. Each year, over 500,000 students use Carnegie Learning’s mathematics curricula.