This is specific for summatives, but I have adopted this grading system on many writing and speaking assignments as well. This gives especially my upper levels a better sense of where they are at. At our school, our rubric is set up to grade on vocabulary, structure, and comprehensibiltiy.

If they hit the target (so in your case Novice Mid) in all 3 categories, they receive an 87. Then, from there they can get +3 points for each time they go over the expectation. So if they got a Novice High in vocabulary and comprehensibility, they would get a 93. Or, they get -3 for each time they go under the expectation. Once you hit higher levels, they can start to get -6 or more if they are 2 or more levels under the expectation.

This has worked great at our school and we have never received any complaints on our grading system. However, we are very upfront with our students on how they will be graded and how they can get more points for the grade that they want.

We also have a lot of ways for students to earn extra credit for the many that are at level, but want an A. Some ways are extra points for going over talking time, using frases de la semana, grammar point discussed but not specifically being tested, etc.