This efficacy study was designed to examine the traditional FOSS curriculum (Delta Publishing, Full Option Science System/FOSS, magnetism and electricity, structures of life, and water modules, 2005), and the new ASK/FOSS curriculum (magnetism and electricity, structures of life, and water modules, 2005), a revised version of the original FOSS curriculum, to determine impact on student learning. The enhanced curriculum includes slightly revised instructional materials and a coordinated embedded assessment system, with components developed to support teachers' on-going assessment of student learning and progress towards specified learning goals. The study involves randomly assigned treatment/control groups of 3rd and 4th grade teachers. Year 3 of the project was the study year for ASK/FOSS Cohort 1 (Arizona), and the pilot (or practice) year for additional schools and teachers, ASK/FOSS Cohort 2 (Arizona, Texas and Washington). This report presents data from both study cohorts. Table 1 summarizes the data sources, and the type of information provided by each instrument, designed to capture the most critical components of the ASK/FOSS curriculum. In the following sections of the report, analyses and findings are presented based on these data sources and assessment components. Appendices include: (1) ASK/FOSS Data Collection Plan; (2) Data Collection Instruments; and (3) Correlation Matrix--All Instruments. (Contains 33 tables and 1 figure.)