The mathematician known for inventing a controversial way to measure teacher effectiveness has died at age 74. Even Bill Sanders' obituary tries to explain how TVAAS works.
Sanders boiled it down when WPLN visited him at his home in Columbia for a 2014 interview.
"The analogy is, you measure the effectiveness of teaching on the progress that students make, as opposed to some characteristic directly of the teacher," he said.
Sanders' statistic specialty was cattle — after all, he grew up on a dairy farm in Shelbyville. But he applied his predictive breeding formulas to classrooms to help show how much a teacher was helping a student, rather than relying on outright scores on a test.
Sanders' model for value-added growth has been used in Tennessee since 1992 and has since been adopted in other states. But teachers unions have resisted it all along the way, saying it fails to take into account poverty and family situation. The head of the National Education Association even called Sanders' value-added system the "mark of the devil."
Sanders said he tried not to take the criticism personally. His funeral was held Sunday. His obituary says he believed, simply put, that educational influence matters, and teachers matter most.