- Teachers should be paid based on how "good" they are.
- We should measure teacher effectiveness by how much their students learn.
- We should measure student learning through standardized tests.
Thankfully, most people would now not be surprised to hear an argument against 3 following logically from 2, so I don't need to make that argument. Less common is the understanding that 2 does not follow from 1 - a good teacher may still not cause students to learn. This faulty step comes from the idea of students as vessels into which the teacher pours their knowledge (the "banking" idea of education attacked by Paulo Freire), a notion which is now outdated. Instead, current educational theory recognizes that student learning requires work on the part of the student as well as the teacher. Student learning requires an atmosphere in which the student can concentrate and be stimulated. Student learning requires a previous knowledge base for the student to build on. And there are many other variables which affect student learning and take into account the reality that a student without enough to eat is less likely to learn than one who isn't distracted by hunger and other basic needs. None of these other dimensions of the problem have anything to do with the teacher (despite the teachers who go above and beyond to pay for food for their students out of their own meager salaries, knowing that their work is ineffective otherwise). Paying teachers based on much their students learn is assuming correlation without any evidence supporting it. (See Medley's 1982 article "Teacher Effectiveness" for more on this.)
Still, despite these issues, teachers can be evaluated in class by principals or other supervisors. It will require more and sustained work on the part of these administrators, so that teachers are not condemned by one bad day. But these steps are worth it. Teachers need to be paid more. The profession needs to be viewed as such to attract the best and create the best school systems. We're capitalists - it all comes back to pay.