More VAM scores controversy: Math oversight could cost teachers jobs, pay raises
School districts likely will mislabel teachers as “effective” or “unsatisfactory,” teacher advocates say, if school officials rely on the state’s newly released teacher value-added scores, which measure a teacher’s impact on student learning.
The scores, which extend to many digits beyond a decimal point, aren’t as precise as they look. They come with an important caveat called the standard error.
It is a statistical way to measure how stable or variable a set of numbers is, to help people decide how certain they can be of the numbers.
Up to 73 percent of the state’s teacher value-added scores, or VAM scores, have high standard errors, and up to a half may be high enough to make their scores possibly too close to call, experts said.
That means a teacher who is viewed as above average or below average may be average after all.
“These standard errors are so large that … it would be unfair to sort teachers into categories based on these numbers,” said Donna Mohr, a statistics professor at the University of North Florida who specializes in growth curves and