The proposed model makes no assumptions about the "average" teacher -- it proposes a simple metric applied to student performance. Under this metric, some teachers would get a positive score because their students' scores improved more than the average. Others would get a negative score because their students' scores improved less than the average.
> would this model prevent it?
I don't know, but the goal of the model is to prevent this, or even reverse it -- that is, the best teachers would want to work with the least advantaged kids, because arbitrage -- it should be easier to make a difference for kids starting at a low performance level, and harder to make a similar difference with kids starting at a higher level.
I don't know whether this works even a little bit in practice, but the thinking sounds promising.
> The proposed model makes no assumptions about the "average" teacher
Sure it does. How else is the teacher_skill rating calibrated?
> the best teachers would want to work with the least advantaged kids
Why is this necessarily a good thing? Shouldn't there also be an incentive to have the best teachers work with the brightest students, to ensure that those students are actually challenged instead of just skating through school?
The proposed model makes no assumptions about the "average" teacher -- it proposes a simple metric applied to student performance. Under this metric, some teachers would get a positive score because their students' scores improved more than the average. Others would get a negative score because their students' scores improved less than the average.
> would this model prevent it?
I don't know, but the goal of the model is to prevent this, or even reverse it -- that is, the best teachers would want to work with the least advantaged kids, because arbitrage -- it should be easier to make a difference for kids starting at a low performance level, and harder to make a similar difference with kids starting at a higher level.
I don't know whether this works even a little bit in practice, but the thinking sounds promising.