Science education reforms, such as the introduction of inquiry into the classroom, represent second order educational changes (12,13). Although first order changes require small alterations of existing practices, second order changes challenge the structures and rules of schooling. Research on second order change has shown that, despite best efforts, most reforms are “either adapted to fit what existed or sloughed off, allowing the system to remain essentially untouched” (12, p. 343). RET’s seem to hold the most promise for supporting second order changes as represented by inquiry; however, given the difficulty in achieving and sustaining second order changes, the need for research into their influence is clear. This research project will focus on analyzing RET programs through description of their essential features, their efficacy in fostering teachers’ understanding and enactment of inquiry, their interaction with the personal characteristics of participating teachers, and an examination of the influence of teaching through inquiry on student learning in science.