Merit pay would have to be based in some way on performance of the teachers, but how would you measure that in a quantitative way?
- If you measure based on marks, would the teachers not have an incentive to push up the marks? Teacher bonuses would be very dependent on the school they are in and the mix in their class.
- If you measure based on the improvement of students in this year compared to last year the teachers would have an incentive to put all their resources on students that can come the farthest.
- If you measure based on something like the foundation skills assessment, you would have to have it for all grades and you would have the whole school system oriented towards one set of tests.
I can not think of any qualitative measure on how you would rate teachers. These are all subjective and who would be the judge? There is no way you could write this out so that it would ever be fair.
I certainly have my opinion on which teachers I have seen are good ones and which are bad, but much of that will have to do with personality and the fit with my kids. The teaching needs of all of my boys differ and a teacher that is good for one would not necessarily be good for another one.
There are some rare exceptions of teachers I have had the pleasure of dealing with that have been stellar, clearly brilliant in what they do. But how I do not see how their skill can be empirically and fairly measured.
Teachers, like most professions, do not do a job that allows for an easy method to objectively show they are better or worse than others. The same is true of comparable professions like lawyers, doctors, dentists, engineers, accountants and others. In all of them I can give you my opinion who I think is good and who I do not like, but I have no way to give you that on a ten point scale.