The big news in New York today is the release of the Teacher Data Reports (TDRs) for some 18,000 teachers. These were ratings that the city calculated using a value-added model. The New York Times is going to publish all the scores, including the teachers’ names, on their website.
Much to the surprise of most people following the issue, both Bill Gates and Michelle Rhee’s StudentsFirst expressed that they did not think it was a good thing to release this data. Wendy Kopp also opposed the release of this data, as she did a few years ago when they did a similar thing in Los Angeles. Most people who are opposed to this are because of the known error rates. Gates and Kopp don’t mention those when they say the data should not be made public. They just say that it is just one measure and that shaming teachers will kill morale. They can’t mention the error rates since that would destroy one of the pillars of the reform movement — that teachers must be held accountable if they do not get those test scores up.
Today, the day of the release of the New York City data, I received an email that I did not expect to come for at least a year. In D.C. the evaluation process is called IMPACT. About 500 teachers in D.C. belong to something called ‘group one’ which means that they teach something that can be measured with their value-added formula. 50% of their evaluation is based on their IVA (individual value-added), 35% is on their principal evaluation called their TLF (teaching and learning framework). 5% is on their SVA (school value added) and the remaining 10% on their CSC (commitment to school and community). I wanted to test my theory that the value-added scores would not correlate with the principal evaluations so I had applied under the Freedom Of Information Act (FOIA) to D.C. schools requesting the principal evaluation scores and the value-added scores for all group one teachers (without their names.) I fully expected to wait about a year or two and then be denied. To my surprise, it only took a few months and they did provide a 500 row spreadsheet.
I made a scatter plot with the principal TLF on the x-axis and the value-added IVA on the y-axis. What came up confirmed my expectation that these would not correlate. It looks like a blob or, maybe, with some imagination a Buffalo facing to the right. There is a slight upward trend, but the correlation coefficient is only .35, which is quite low. Here is the scatter plot.
Perhaps this is why they recently announced they are changing the IMPACT process. It will be too late, of course, for all the teachers who were fired over this and also for the teachers who voluntarily left the system rather than let 50% of their evaluation be left to random chance.