[readthenotes1]

"Because most did not teach tested grades and subjects, the researchers also looked at evaluation ratings. Both groups of teachers received similar marks from their supervisors."

That is, they cannot speak to how effective the teachers were as educators, only how disruptive they were as employees.

[germinalphrase]

Assessing educator effectiveness is not a solved problem. For instance, the Gates Foundation made a full throated effort to research and develop a quantifiable measure and failed. In the end, they released a set of holistic, observable behaviors/practices that they believe are associated with teacher effectiveness. It’s a hard problem.

[readthenotes1]

I completely agree. For one thing, they're probably looking at the wrong things since student effectiveness will dominate teacher effectiveness, and that is where the hard problems come (knowing what to look at, what to measure, proxy measurement error, and measurement distinction)