Data hounds continue to search for a measuring stick to identify teacher quality.

They can’t believe they are on a fruitless hunt, like trying to find a barometer or yardstick to say which piece of art is best, which doctor is best, which…… as though human judgment means nothing.

Here is Matt Di Carlo summarizing the research on the instability of VAM, meaning that the best teacher this year might be only average next year, or vice versa.