Data-driven instruction began its spread across the country about a decade ago, in the footsteps of the No Child Left Behind requirement that schools administer yearly achievement tests. Those tests didn't help teachers spot and backfill learning gaps, though. Scores came back after everyone had moved on to the next grade, and anyway, the tests…

Despite mixed reviews from many educators--and some researchers--Chicago's retention policy to end social promotion has turned out to be a popular program. Surprisingly, perhaps, its most avid fans are the people most affected by it: teachers and students. Chicago's ending of social promotion was intended to make educators pay more attention to…