Spurred by a succession of reports pointing to the importance of algebra as a gateway to college, educators and policymakers embraced "algebra for all" policies in the 1990s and began working to ensure that students take the subject by 9th grade or earlier. A trickle of studies suggests that in practice, though, getting all students past…

To build on classroom experiments and lectures, Daniel Sweeney has his 9th grade earth science students act out scientific concepts on a 15-by-15-foot mat on the floor of the room. Object-tracking cameras mounted on scaffolding around the space collect data based on the students' movements while immersing them in the experience through a video…