These reports, which rated 12,700 NYC teachers based solely on the 2010 test scores of their students, filtered through a complicated value-added formula, are seen by most experts as highly unreliable, based on false or incomplete data and include huge margins of error.
Even the panel of "technical experts" handpicked by DOE said they could not endorse the use of these for accountability, promotion or tenure" purposes, pointing out that "test scores capture only one dimension of teacher effectiveness,  they are not intended to serve as a summary measure of teacher performance" and that "there are likely to be additional factors not yet considered that influence student achievement."
There is no other profession in the public or private sector in which this kind of unreliable and potentially damaging information is made public, and the main effect would be to further undermine teacher morale -- already at an all-time low in this city.