Thompson: Value-Added vs Objective Evaluations
Richard Rothstein's "What Research Really Says on Teacher Evaluation," in the Washington Post, reviewed the large body of social science that explains why value-added estimates are not valid for individual evaluations. Rothstein then made the common sense point that value-added will poison the well and undermine more appropriate metrics. He concluded, "one thing of which we can be certain: Armed with knowledge of teacher value-added scores, it will be much harder for principals to observe and evaluate teachers objectively."
On the other hand, there will be principals with the integrity to resist abuses due to flawed value-added estimates. Award-winning principal, Carol Burris, another guest blogger at Valerie Strauss' The Answer Sheet, reported that 500 principals returned surveys regarding the first year of New York's value-added ratings of their teachers. Burris explained, "Seventy three percent of respondents said that the 'ineffective' label assigned to some of their teachers was either not a very accurate or an inaccurate reflection of that teacher."
Burris cited one principal who wrote: “Two excellent teachers who volunteer to take on my toughest students got an ineffective. Their hearts were broken. So was mine.” Some principals "stated that they would change their teacher’s assignment next year and assign them less needy students so that they could protect these excellent teachers from the ineffective rating."
I expect that Rothstein and Burris are both correct and we will see the full range of human reactions to a flawed effort to subordinate human judgment to an algorythm. The real problem will be the temptation of many (though not necessarily the majority) to Rothstein's question of whether principals will "tend to sink unfavored teachers with high value-added?"
In every neighborhood high school that I know, there is no doubt about which classes are "dumping grounds," where troubled students are shoved into a side hall in lieu of providing them the services that they desperately need. Real world, in those types of schools, how many principals will resist the temptation to rid themselves of dissenters by dumping those teachers into classes where it is virtually impossible to meet growth targets?-JT(@drjohnthompson)Image via.