In the discussion of the SGP data that Brian Davison sued out of the State Department of Data Suppression, I’ve been focused on the awful teaching (*e.g.*, here, here, and here) that the Virginia Department of “Education” and the Virginia “Education” Association have been attempting to conceal. But their efforts to hide teacher performance data from the taxpayers who are paying the teachers have another outrageous effect: They suppress the identities of the many great teachers in Virginia’s public schools.

Having looked at the 43 teachers with the worst three-year average math SGPs, let’s turn to the 43 with the __best__ averages:

The “Row Labels” column contains the (anonymized) teacher IDs. The “Grand Total” column is the three year average for each teacher. The “Grand Total” row reports the statewide average of each column.

All but three of the 43 teachers at the bottom of the SGP list damaged Virginia schoolchildren for only one year; almost half of the teachers in the present list helped educate Virginia schoolchildren for more than one year.

Here are the Top Ten who taught all three of the years for which we have data.

Notice that all but two of these got better performances from their students in 2014 than in 2012. And, of those two, No. 115415’s even 99 in 2012 and much lower average suggest only one student (of doubtful statistical significance) in the first year and substantial progress over the second two years.

The preponderance of NoVa suburbs in this list raises the question whether those divisions have better students, or better teachers, or some combination. See below for some data suggesting that there is more learning, and presumably more teaching, is in some more rural districts. In the meantime, here are data for the Top Ten in graphical form.

Or, with the ordinate expanded:

The division averages provide some further insights. Let’s start with the distribution of division mathematics averages for 2014.

As shown above, the mean math SGP in 2014 was 49.1. The division mean was 48.3, with a standard deviation of 6.2.

The Top Ten divisions of 2014 did not include any of the NoVa suburbs.

Neither, for that matter, did the bottom ten.

Here is the entire 2014 math list, sorted by division (Colonial Beach, Craig, and Surry had no data).

When we turn to the division averages by year an interesting pattern emerges: The Top Ten in 2014 all improved from 2012.

Seems to me that a whole bunch of educators should be put on a bus to one of these divisions to find out how to increase student performance in math.

The Bottom Ten in 2014 mostly declined from 2012, except for Franklin and West Point, which improved; King and Queen, which improved slightly; and Galax, which only had data for 2014.

But the Virginia Department of “Education” and the Virginia “Education” Association don’t want you to see these data. Apparently you are not qualified to know what you are getting (or not getting) for your tax dollar.