I completely agree that students need to be held accountable for learning through a method such as assigning grades. I think we were both hitting on a similar point here. It is extremely important that a student knows what they did correctly and what they did poorly on. So if you could set up and fundamentally understand a math problem, but make a small algebraic error, I think it is important that a student knows that they did it correctly other than that small error and receives points accordingly. Then in the future, they will know how to do similar problems correctly. So, that concept of feedback will allow students to gain more from their testing experience.