A few weeks ago I posted a report on Edwize about biases in last year’s Teacher Data Reports. Teachers of high performing math students are 35 times more likely to fall at the bottom of the teacher ranking than at the top. 
Shortly after that, the DOE placed a document on its website that asserts that “…teachers of high-performing students are as likely to have high value-added scores as low value-added scores.”
To me, call me crazy, this is unlikely to be true. First of all DOE charts found in the very same document seem to contradict that (more on that in a minute). What’s more, DOE used a broad definition of “teachers of high-performing students,” and also included some reports that were so unreliable they were not issued to teachers. Let’s go through this step by step.