Prior research suggests that students' understanding of scientific concepts is pre-determined by their reasoning ability. Other efforts suggest that American students' scientific literacy is in decline. One difficulty Bybee (2009) acknowledges is that there are two divergent philosophical models of scientific literacy. The first describes the…

This year the Center on Education Policy analyzed data on the achievement of different groups of students in two distinct ways. First, it looked at grade 4 test results to determine whether the performance of various groups improved at three achievement levels--basic and above, proficient and above, and advanced. Second, it looked at gaps between…