For several years, state governments in collaboration with the National Science Foundation (NSF) have focused on systemic reform in mathematics and science education. These initiatives may focus on three levels of the system--the state, individual school districts, and multiple schools (Kahle, 1997). Regardless of which level is the focus, the challenge for reform--seeking improved and intellectually authentic science education for all students--is enormous. Systemic reform initiatives generally aim at creating policies that may result in new and improved practice for teachers and learners (Cohen, 1995). Teacher professional development has been a primary focus because teachers translate policy into practice. In his analytical review of several large-scale systemic reform initiatives in science and mathematics education, Knapp (1997) urges researchers to explore the contexts and processes intervening between reform initiatives and actual practice in school mathematics and science classrooms. He concludes, To grasp what such reforms may accomplish involves an ongoing dialogue between diverse and powerful ideas about policy-to-practice connections and emerging evidence from instances of systemic reform (p. 227). Studies of educational policy indicate that researchers give much attention to the development and implementation of policies, but they often ignore the evolution of policy (Jennings, 1996; Odden 1991). It is important to study classroom practice and other factors that may mediate between the goals of reform and student learning so that those functions can inform and guide policies to help teachers become effective agents of reform. Because the academic area may influence the dynamics of reform, it is also necessary to examine the policy-to-practice connections in light of the culture of a discipline (Grossman & Stodolsky, 1994). For decades, researchers in science education have demonstrated the importance of inquiry-based instruction for effective learning and urged a shift from the transmission mode of instruction. Researchers have urged teachers to involve students in constructing ideas from observations and in incorporating personal experiences into instruction as well as encouraging interactions with their peers and teachers. Ohio's Statewide Systemic Initiative (SSI) focused on middle school teachers (Grades 5 through 9) who attended 6-week summer institutes to learn science content through open-ended and guided inquiry. Inquiry instruction in the summer institutes was modeled after the work of physicists who have successfully used inquiry to teach basic physics concepts to pre- and inservice teachers (Arons, 1990; McDermott, 1996). A major goal of the SSI reform effort was to change science teaching from didactic to inquiry-based instruction. The instruction and assessment envisioned by Ohio's systemic initiative were consistent with the tenets of the two national science education groups (American Association of Advancement of Science, 1993; National Research Council, 1996). All lessons were designed to help teachers develop an under standing of scientific concepts through the basic reasoning processes that scientists use. Thus, questions such as How do we know ...? Why do we accept or believe ...? What is the evidence for ...? (Arons, 1990, p. 314) guided the inquiries that teacher participants conducted as they carried out in-depth studies of various systems and their interactions (McDermott, 1996). Teachers also designed projects in life science by inquiry institute courses. Current research on pedagogy, pedagogical content knowledge, cooperative learning groups, and equity was embedded in the institutes and their six follow-up seminars during the next academic year. In summary, teachers learned to engage students actively, to focus on and support student inquiry, and to foster a collaborative and equitable learning environment. The basic tenets of Ohio's science and mathematics education reform are * Students actively engage in constructing meaning from what they do; * Teachers guide the construction of meaning through appropriate questions; * Teachers design or select lessons that are connected and represent the central ideas of a discipline and the relationships among ideas, instead of choosing discrete exercises; * Students work cooperatively in groups and learn to develop ideas through discussion with their peers and the teacher; and, * Teachers incorporate various assessment measures that examine student learning from various perspectives at different points in each lesson instead of using only end-of-the-unit, paper and pencil tests. …