NYC's Trojan Horse
It's hard not to view these Teacher Data Reports as a Trojan Horse. Just how is a tool that is designed for capacity-sorting supposed to function for capacity-building? After all, a teacher value-added measure might tell us something useful about which teachers are more or less successful in raising their students' test scores, but it tells us nothing about the specific instructional practices that account for their relative success.
How are Teacher Data Reports supposed to improve instruction? In her videotaped comments to teachers, Amy McIntosh, the Chief Talent Officer at NYC's Department of Education, says, "These reports will provide information that will help teachers and school leaders gain insights about important aspects of a teacher's practice ... Whether individual teachers have a greater influence on the learning of some groups of students than on others ... Finally, we can see what teachers might benefit from development focused on, say, the needs of English language learners, and which teachers might be best positioned to lead that kind of professional development ... We also think they will ... help you think about how you can share the techniques you use with your colleagues in your school or across the city."
Hmm. So the specific strategies for improving teaching practice are what, exactly? Having more successful teachers lead the professional development of less successful teachers? Expert practitioners don't always make expert coaches. Hall-of-Fame pro basketball player Isiah Thomas--unquestioned as one of the best point guards of all time--was a mediocre coach for the Indiana Pacers and New York Knicks.
Here's why. Teaching is an extraordinarily complex activity, with teachers making thousands of decisions in the course of their work. Successful teachers make many good decisions and some bad decisions, whereas less successful teachers make many bad decisions and some good decisions. But the capacity to reflect on one's practice and figure out which of those decisions are good and which are bad is exceedingly rare, as is the capacity to share this knowledge with others. In the absence of this reflective capacity, we're all prone to attribute our successes and failures to our pet theories, which may or may not be correct. A Teacher Data Report that provides reassurance that a teacher is successful will only solidify and reinforce a personal folk theory about the reasons for that success.
Yet the Teacher Data Report provides no evidence whatsoever about why a teacher is successful--the many daily practices that promote student learning. And if a teacher's personal theory is inaccurate, then sharing it with others will not improve instruction, nor student achievement. It could even make things worse, focusing attention on ineffective practices. A tool like the Teacher Data Report that claims to be useful for increasing teachers' capacity to teach students effectively, but instead is only useful for ranking teachers on their effectiveness, is a modern-day Trojan Horse.