The fact this doesn't happen already is just plain wrong. A teaches salary should be heavily influenced by their performance.
To many teachers go to school to eat their lunch. They have little regard for student wellbeing or education. I believe we have a low standard of teaching in NZ and I'd like to see that change.
If anyone in our society should be placed on a pedestal it's a good teacher. They should be publicly recognized for their contribution. The dodgy ones... Well they need to be publicly recognized as well.
This our hard earned tax's that are being spent here. Teachers must be held accountable for student opinion, student academic success, and the schools success overall. These three factors should contribute to determining their salary.
It is unreasonable for teachers to be evaluated simply based on how well their students perform on standardized tests. Students come from different backgrounds, and it is unreasonable to assume that a teacher in an affluent neighborhood should produce students who score identically to students who attend school in an impoverished neighborhood.
However, it is also important that teachers should be evaluated for quality control. A bad teacher may do more harm to a student than can easily be predicted, and a good teacher may help a student to become a greater success in life. Some degree of responsibility to ensure that students encounter as many good teachers and as few bad teachers as possible must fall to the schools.
Perhaps a reasonable starting place for designing a system of metrics for teacher evaluations would be to test students at the beginning and at the end of each term and rate teachers based on how much their students improve. Alone, this is probably an insufficient method of evaluation, but at least it takes steps to remove the bias of evaluating very different teachers by uniform standards.
Since the main objective and responsibility of the teacher is to motivate students to learn the subject I believe that teachers should be evaluated on the performance of students. If the majority of students fail the class then the teacher should hold responsibility for the mass failure. He should take actions and revise his teaching methods in order to help students to do better in class.
Some students' poor performance is not the fault of their teachers. Some kids are genuinely not good at test taking, and others have personal problems that prevent them from performing well. The parents of poor performing kids should also take some of the responsibility. There are some students that teachers just can't help.
If it were the case that the sole reason for a student's success was the ability of his/her teacher, then it would make sense to evaluate teachers by students' success. However, that is not the case. Some students succeed in spite of teachers' worst failings, while others fail in spite of teachers' best efforts.
A student's success needs to belong to the student, not the teacher. All this isn't to say that teachers should not be evaluated, but they should be evaluated by professionals who know and understand what makes a good teacher.
Let's imagine two scenarios.
Scenario 1: a teacher gets a job in a nice part of town, where the upper middle class students get higher grades on average than most of the country. He goes to work every day and teaches his class, rarely getting any trouble from the students and at the end of the year he picks up a cool 50K.
Scenario 2: a teacher gets a job in the poor side of town, where high crime rates, gang activity and lack of parental help gives students a much lower chance of succeeding at school. He struggles all year long to get his class to pass their exams and at the end of year, some have dropped out, some have failed and a few succeed. He picks up a significantly lower paycheck even though his job was significantly more difficult than the teacher who was teaching in the nice side of town.
Does this seem right to you?