Teacher Salaries

Agreed that teachers should be paid more, especially the good ones. If you guys think these numbers are bad, according to my prof, my university pays sessional lecturers to teach 100 people classes roughly 35k a year, which is absolutely horrible.

That being said, I would be fine if teachers were paid based on results: The better teachers get paid more instead of all teachers getting paid a handsome amount for doing a crappy job.

How do you suggest they differentiate between bad classes and bad teachers?