How might one evaluate an educational curriculum?

I believe that one should always be evaluating curriculum. I don't think it would be fair to the students if a teacher always used the same readings and the same assignments for every class he or she teaches in any given year or discipline. Evaluation would be based on student needs, student location, student ability, and student capability. I don't think it would take rocket science to see that one part of the curriculum is not working for a particular group of students or school. Teachers should be held accountable for evaluating the curriculum that they are teaching. I have a friend who taught in northern Alberta where a teacher's ability is based on how many students pass the classes that they teach. What if our salaries were based on how much a student learned that week or month or year??