magicalclick said:
I really think good teacher and bad teacher cannot be measured. I believe everyone has a role to this world, whether it is a gardener or a scientiest. Our economy requires a healthy mix of edcucation levels and job opprotunities. What's happening is that it is no longer balanced after everything is "recommended" to out source with tax cut.

Good teacher and bad teacher? I would say the ones that I respect the most is not the one who offers better knowledge about the subject, but some casual suggestions that show me the right diection where I should be heading. I don't care if someone failed at the subject. I care if the teacher can motivate students to have a dream or purpose. This is something no one can measure.

Better education mostly provides smarter zombies, not dreamers. Without American Dreams, US will lose its edge.
I think you actually can measure the effectiveness of teachers to a large extent.
Do students learn?
Teachers are there to teach things...if they don't achieve that, they are failing.
To some extent it's easier to identify good teachers than bad ones (except very bad), but I do think it's worthwhile  trying to identify who's getting good results and what they might be doing to achieve those results.