If they test students at the beginning of the course and the end of the course, they could objectively evaluate how good each teacher is. Anyone who argues against the practice is against objective analysis of teachers.
Because if your dad's in prison and your mother hung herself and now you're in your second foster care home already, and your foster care dad is abusing you,
YOU CAN'T LEARN. You don't give a crap about math, your BRAIN doesn't give a crap about math. Your brain, in survival mode, does not have room for it and won't make room for it. That is brain wiring, it's neuroscience. It's brain research. Look it up if you can't believe me.
So. Is that the teacher's fault? Did he not teach math well enough for Johnny with the prison dad and the suicide mom and the abusing foster care parent to learn math?
I suppose so, because that's where we are now. It's all the teacher's fault.