Some communities have decided to base evaluations of teachers on students' test scores. It's these evaluations that determine how much teachers will be paid. I don't think this is a very good idea for several reasons.
First of all, if teachers' salaries are going to be based on how much students learn, then some teachers will start to teach their students only what they need to get high test scores. This means that students will miss out on a lot of education that can't be measured on a test.
For instance, one of the best methods to help students understand a subject is encouraging them to discuss it. A common practice is to divide the class into groups, have each group discuss the subject, and then have them report back to the whole class. This kind of shared learning can lead to a fuller understanding. It also teaches students how to discuss and debate ideas. However, it doesn't supply facts to show off on a test.
Another problem with basing teachers' salaries on how much their students learn is that teachers may ignore students who have learning difficulties. Some students learn more slowly than others and need more personal attention. If a teacher is worried about tests, he may feel he has to push the majority of the students to cram facts. That effort will take all his time. He won't be able to help the less able students.
It's true there are teachers who "burn out" after many years teaching and just don't care how much their students learn. Basing their salaries on their students' test scores may improve their efforts. However, it's not fair for the majority of teachers. They deserve and need to be judged by other criteria.
Education is one of the holiest occupations in my view. I disagree with that teachers should be paid according to how much their students learn. Although teachers are important for students, the most important part for learning knowledge is students themselves.
Different teachers has different style, so it is hard to evaluate how well each teacher teaches according to how much students learn. As nobody would have the same character, teachers also have their own teaching styles such as humorous, gentle, strict, to name a few. Maybe some students like humorous teachers, while others prefer a gentle one. But probably the students of a strict teacher could give good results in their study, even though these teachers teach the same thing. We could not say that the strict teacher should be paid higher than the gentle teacher, since we know that the students have learned more because they were afraid.
On the other hand, how much or how well students learn depends on students themselves. In a school, it is easy to see that some students are with high marks, while some others have lower marks. A teacher is a person who direct students how to learn. Students should do much more works. The more attention students pay, the more knowledge they learn. The hard-workers probably get higher scores. Students' learning results depend on individual students' intellectual abilities and the time and energy that they put into learning. Sometimes it has nothing to do what how well the teachers taught. In addition, knowledge that students learn not only comes from the teachers, but also from many sources. Family influence, extracurricular reading and out-class teaching are some of the sources that can provide students with knowledge.
In sum, although teachers are important in students' education and learning, there are many other factors that decide how well students' learn. So it is unfair that teachers are paid according to how much their students learn.
