Tennessee’s largest teachers’ union is trying to head off a plan that calls for using student achievement data in determining whether a teacher can keep her license.
Gera Summerford, president of the Tennessee Education Association, says the numbers – known as TVAAS – are useful but not 100-percent reliable.
“Tying license renewal directly to TVAAS scores is not appropriate,” she said at a press conference Wednesday. “And we challenge the idea that a teacher’s score in a given year is a valid indicator of a teacher’s future performance.”
The state Board of Education is set to make a final decision on Friday about tying licensure decisions to TVAAS data, which are not straightforward standardized test scores. They’re more like estimates of how much a student has improved, requiring an equation using matrix notation.
Summerford points to a 7th grade science teacher in Weakley County who has been all over the five point scale – going from a five to a one to a four to a five and back to a one.
Mistakes ‘Will Happen’
Some teachers have even experienced revisions for past years, similar to jobless data when the unemployment rate for prior months is revised up or down once more information is available.
If the state board approves this change, two years out of three at the bottom of the scale would revoke a teacher’s license. And some teachers will be swept out who shouldn’t have been, says Vanderbilt Peabody professor Dale Ballou.
“It will happen. I don’t see how that could be avoided,” he says.
Ballou – who is a former middle school teacher with a PhD in economics – says TVAAS data is a good predictor of how a teacher will perform in the future. But as with any predictive model, there will be mistakes, particularly when there are 60,000 public school teachers across the state.
“You’ve got an issue here,” Ballou says. “You’re ultimately trying to do this for the benefit of the students being served by this system. So you’ve got to ask yourself, on balance, are we going to come out better or worse using a system like this to weed out ineffective teachers?”