This project is creating materials to promote conceptual development for calculus students, by helping instructors to raise the visibility of the key concepts, to stimulate student peer-to-peer discussion of concepts, and to connect calculus concepts to what students know and understand about their world. In addition to creating materials to enhance student learning, the project is investigating the hypothesis that tapping into mathematicians' emphasis on conceptual understanding, and their beliefs about how mathematical understanding is built, can motivate faculty to experiment with new methods and approaches to enhance student learning. In this case the approach is modeled after Mazur's reformation of introductory physics course through the use of ConcepTests that actively engage students to think about, discuss, and clarify their understanding of basic physical concepts. Student peer-teaching is also featured.