New York's teacher union, the UFT, has joined with the NYC Department of Education to launch a pilot program that will effectively rate all 18,000 of the city's fourth through eighth grade teachers on how well their students improve in reading and mathematics. Using student achievement test results as the measure, these teachers will be rated above average, average or below average.

The announcement comes as a surprise since the union's president, Randi Weingarten, has been stalwart in her opposition to attaching student data to teacher evaluations and even succeeded in persuading the New York State legislature last spring to prohibit by law the use of such data. However, NYC has been determined to find ways to use student data within the confines of the new law, and the UFT doesn't really have much control over those.

So how will the data be used? Principals will be privy to the reports, surely affecting decisions around teacher assignment within the school and professional development needs. Teachers will receive an individual report of their own students' data, broken into subgroups, to help them do a better job. Though voluntary, NYC is encouraging teachers looking to transfer to other schools to share the reports with interviewing principals.

For the time being, the UFT did manage to get NYC to pledge that the data won't be paraded before the public in the town square. But it seems that Deputy Chancellor Christopher Cerf would like to eventually go public with it, calling such a move "a powerful step forward."

We wonder why there is such interest in broadcasting job performance. A person's job evaluation--which is effectively what these data represent--is between the boss and the employee, in this instance the school principal and the teacher. Why should the public get access to information that in any other setting is considered to be private? Collect the data, use the data for making important personnel decisions, but don't broadcast it.

The union's press release says the agreement "once and for all closes the door on using student test score data to evaluate teacher performance." Actually, the legislative ban is set to last only two more years, at which time the district may do as it pleases, unless the legislature decides again to intervene.