This research project consists of a randomized experiment in St. Petersburg Catholic Schools. The question being addressed by the research is whether "Scott Foresman Science" is as effective as the current curricula being used in the participating campuses of the Roman Catholic Diocese of St. Petersburg. The research focuses on 3rd, 4th, and 5th grade students. The outcomes were measured by student achievement on standardized tests administered at the beginning and end of the project. Two test areas were selected as the outcome measures: Science Concepts and Processes, and Reading Achievement. The overall comparison between Scott Foresman Science ("SFScience") and the program used in the control classroom was just the first step in the investigation. The authors also aimed to understand how the product was implemented and other ways that science instruction differed between the two groups. In addition, they sought to understand how characteristics of the students and of the teachers may have moderated the impact, that is, whether "SFScience" was more effective with students or teachers with differing abilities or experience. Finally, they explored the extent to which the groups differed in amount of time devoted to science or specifically to inquiry and whether those differences may help to explain the results. The design of the experiment reflects the requirements of the No Child Left Behind Act, which directs schools to consult reports of rigorous research in making adoption decisions about instructional programs. The study was designed to provide useful information to support local decisions that take into account the specifics of district characteristics and their implementation of the program. This report provides a rich description of the conditions of implementation in order to assist the district in strengthening its program and to provide the reader with an understanding of the context for the findings. (Contains 32 tables, 5 figures and 4 footnotes.)