In "The Irreplaceables," TNTP researchers argued that America's urban schools take a negligent approach to teacher retention, losing too many of their very best teachers--their "Irreplaceables"--and keeping too many of their weakest teachers, year after year. A combination of weak school leadership, poor working conditions and restrictive policies…

There is no shortage of research on the importance of good teaching. For decades, study after study has shown that there are large differences in effectiveness from one teacher to another and that these differences can have a lifelong impact on students. A recent study that tracked 2.5 million students over 20 years determined that those with…

"Irreplaceables" are teachers who are so successful they are nearly impossible to replace, but who too often vanish from schools as the result of neglect and inattention. To identify and better understand the experience of these teachers, the authors started by studying 90,000 teachers across four large, geographically diverse urban school…

This paper presents myths as well as facts about value-added analysis. These myths include: (1) "Value-added isn't fair to teachers who work in high-need schools, where students tend to lag far behind academically"; (2) "Value-added scores are too volatile from year-to-year to be trusted"; (3) "There's no research behind value-added"; (4) "Using…