Thursday, March 28, 2013

Why rating teachers by test scores won’t work

From Jay Matthews - Washington Post - Class Struggles - Click Here

Posted at 01:39 PM ET, 05/13/2012

"I don’t spend much time debunking our most powerful educational fad: value-added assessments to rate teachers. My colleague Valerie Strauss eviscerates value-added several times a week on her Answer Sheet blog with the verve of a Samurai warrior, so who needs me?

Unfortunately, value-added is still growing in every corner of our nation, including D.C. schools, despite all that torn flesh and missing pieces. It’s like those monsters lumbering through this year’s action films.We’ve got to stop them! Let me fling my small, aged body in their way with the best argument against value-added I have seen in some time.

It comes from education analyst and teacher trainer Grant Wiggins and his “Granted, but .  . .” blog. He starts with the reasons many people, including him and me, like the idea of value-added. Why not rate teachers by how much their students improve over time? In theory, this allows us to judge teachers in low- and high-income schools fairly, instead of declaring, as we do, that the teachers in rich neighborhoods are better than those in poor neighborhoods because their students’ test scores are higher.

I have seen this sham firsthand over many years,” Wiggins writes. “Lots of so-called good N.J. and N.Y. suburban districts are truly awful when you look firsthand (as I have for three decades) at the pedagogy, assignments and local assessments; but those kids outscore the kids from Trenton and New York City, even though both city systems have a number of outstanding schools and teachers.”

Money makes a big difference. “For every $10,000 increase in family income, SAT scores rise approximately 15 points,” he said."