Top 10 teachers in Florida illustrate how messy and absurd the new teacher data is

This week of February 24, 2014 the State of Florida was forced to dump a boat load of data on its teachers into the public domain (It lost a law suit to Times Union newspaper in Florida, which requested the data). Nearly every public and charter school teacher in the state is named. And next to each named teacher is a “value added measure,” a figure that’s supposed to represent how effective he is based on how much his students’ reading and math test scores surpassed what you would expect them to be.

It starts with a complicated formula that predicts how much you expect each student to learn during the year.  I’m not quite clear on how the formula factors in where a student started. It’s usually easier to show larger gains off of a low starting point. But much harder to show gains from a high starting bar. I’ve already seen at least one post from a teacher of “gifted” students, complaining that she now has a negative value added measure because her students started the year with very high test scores. Her students’ scores increased at the end of the year, but not by as much as the complicated formula predicted they should have. It’s possible that this teacher isn’t very good. But it’s also possible that she’s a great teacher. It would be fascinating to calculate how many of the teachers of advanced students received negative value added scores.

One illustration of how bad this data is is simply to look at the top 10 list of teachers in the State. (I sorted the entire database by value added measure and made this table).

It’s not immediately apparent what subjects each of these teachers teach but 8 of the top 10 don’t even teach the courses that are measured by the state’s math and reading tests that were used to calculate the value added measures. They could have been art or physical education teachers. For the teachers that don’t teach a subject measured on the test, the state still uses the students verbal and math test scores. It’s just that other teachers taught those subjects to these students.

I happened to Google a few of the teachers on the list above. It turns out Lynne Burrier-McDill is a math teacher. But when you look up the details behind her stellar value added measure, only her students reading scores were used. Go figure.