After co-teaching in inclusive classrooms and witnessing the benefits of inclusion done well in schools and school districts around the country, I am convinced that most students achieve more in the general classroom with an environment of excellent teaching. The trend towards tracking students in leveled classes based on test scores and ability has not been validated by credible research over time. The research on tracking/leveling is about as inconclusive and controversial as the research on homework. Find a study that claims students perform best in leveled classes and there's another one that states that students perform better in heterogeneous classes. Read how four schools faced the challenge of implementing RTI