That's the crux, the worst and best teachers will be evaluated almost the same. You need some kind of additional flag to identify this, and unfortunately the ne

That's the crux, the worst and best teachers will be evaluated almost the same. You need some kind of additional flag to identify this, and unfortunately the next class isn't always possible. Another idea would be a follow up survey 5+ years after the student fraudsters. This is possible as most professors teach for longer than 5+ years.