In the previous post, John Butcher brought to light some incredibly important data long secreted in the Virginia Department of Education — Student Growth Percentile (SGP) scores. There are two aspects to this story. First, the data will bring unprecedented accountability to Virginia schools and school divisions. Second, it is a cautionary tale of how the educational establishment resists transparency that makes that accountability possible.
Brian Davison, who works in business intelligence and software management, had two children in the Loudoun County public school system when he filed a Freedom of Information Act request in 2014 to obtain the score. The Loudoun County school superintendent rejected the request, but Davison won in a lawsuit filed against the Virginia Department of Education in Richmond Circuit Court.
The publication of raw SOL scores never resulted in much accountability. SOL numbers are so heavily influenced by the socio-economic status of students (accounting for about 55% to 60% of the variability between schools) that school administrators could plausibly argue that they aren’t responsible for low scores — the economic disadvantage of their student body is. SGP scores get around that excuse by comparing the progress of students, regardless of socio-economic status. In effect, it measures education value added.
As Butcher’s post clearly shows, some school systems out-perform the norm by wide margins, while others under-perform. An analysis of individual schools probably would show the same thing, as would an analysis of individual teachers.
There are many idiosyncratic reasons why a particular student might lag or surge ahead in his or her performance in a given year, so one has to be extremely careful drawing conclusions from small numbers. That makes the data somewhat problematic for assessing the performance of teachers, especially young teachers who have taught only a year or two. However, after enough years, a teacher should have taught enough students that statistically valid conclusions can be drawn about his or her effectiveness. Another issue: Data should be anonymized in order to protect the privacy of school students.
In very rough numbers, schools teachers, principals and administrators account for roughly 40% to 45% of the variability in student performance. No one expects them to perform miracles, but there is little doubt that they can do better. A critical step is identifying which teachers are consistently doing well and which ones are doing badly in order to incentivize the good ones to stay and the bad ones to leave. Another step is identifying which principals are doing a good job, like Tina McCay at Goochland Elementary School (mentioned here). Finally, voters need data to judge the performance of senior school division administrators and school board members.
I’m doubt the story will end here. There will be endless haggling over how to interpret the numbers — and that’s how it should be. But be not mistaken: This is a game changer. Citizens and parents now have a tool of unprecedented power to cut through the dodging and weaving, the hedging and prevaricating, to hold educators accountable. Now let’s go out and use it!