OK, if you want a metric that might work ... testing a year after the teacher is gone.
If you test while the teacher is in charge, they will encourage the student to game the test. This has short-term gain and long-term pain. If you reward teachers for how well the student retains their knowledge (long term), it should work better.
That won't stop teachers pressuring their co-workers to teach to the test, or principals from telling teachers to teach the test, but it helps reduce it. You could rate schools on how well students do 1 year after leaving, to keep the principals in line. I'd guess teachers will just fob off their co-workers.
OK, if you want a metric that might work ... testing a year after the teacher is gone.
If you test while the teacher is in charge, they will encourage the student to game the test. This has short-term gain and long-term pain. If you reward teachers for how well the student retains their knowledge (long term), it should work better.
That won't stop teachers pressuring their co-workers to teach to the test, or principals from telling teachers to teach the test, but it helps reduce it. You could rate schools on how well students do 1 year after leaving, to keep the principals in line. I'd guess teachers will just fob off their co-workers.