Part of the foundation for the research in physics education house of physics was the work of Robert Karplus and Arnold Arons in the 1970s. They expressed a strong concern about conceptual understanding and mature reasoning of students. Karplus led a team of AAPT members to produce a workshop, Physics Teaching and the Development of Reasoning, that was published by the AAPT in booklet form in 1975. That work was broadened to include other college disciplines and was offered on many campuses for faculty development activities for more than a decade. This book, with the AAPT booklet in Appendix B, brings together those broader materials along with new chapters to show how today\u27s interest in interactive learning is based on this earlier wo...