He cites positive research on two programs using this approach – Reading Assessment and Math Assessment – and reports on a systematic study comparing different interventions aimed at closing the achievement gap – charter schools, voucher programs, an additional year of school, various high-quality pre-school programs, full-day kindergarten, class size reduction, value-added assessment, summer school, teacher salary incentives, teacher experience, teacher PD, longer school day, computer instruction, tutoring, and school reform. Rapid assessment is dramatically more successful at raising student achievement than any of the others.