This study, conducted by the Consortium for Policy Research in Education (CPRE), reports on the impact of the America's Choice school design on student standardized test performance in Duval County, Florida. We present the results of the first two years of the impact of America's Choice in Duval County in elementary and middle schools in writing, reading, and mathematics using test data from 1999-2001. To detect the effects of America's Choice on student learning, we compared the gains in performance of students in America's Choice schools to those of students in other schools in the district. We employed two statistical techniques in order to make the comparisons as fair as possible. First, we controlled for a variety of student and school demographic characteristics, including prior student achievement, in order to isolate the influences of America's Choice on student learning during a one-to-two year period. Second, we used a statistical method called multi-level modeling that allowed us to appropriately model the fact that students are nested within schools and to take into account the fact that we were looking for the effect of a school-level reform effort using individual-level student data.