I realized when I started teaching in the IB system that a lot of changes were going to have to take place, but what I hadn't realized was that my grading scheme would involuntarily shift towards the mode of Standards-Based Grading.
My understanding is that in MYP (Middle Year Programme, which runs from 6th through 10th grade), students are graded based on four assessment criteria: Knowledge and Understanding (out of 8 points), Communication in Mathematics (out of 6 points), Reflections in Mathematics (out of 6 points), and Mathematical Modeling (out of 8 points). A sort of weighted average of all four criteria of assessment results in their final grade in the class, which is out of 7 possible points.
One clear advantage of this system is that it makes it very clear for these MYP students, which of the four categories they need to focus on and improve. (Hence, I say it's more SBG-style.)
What is very interesting to me is that a typical quiz that I give may only cover two assessment criteria (Knowledge and Understanding, and Communication in Mathematics). I look at their overall performance on the quiz, and if they understood just over half of the material, for example, I would assign a 5 out of 8. I also look at the amount of work shown, plus the one or two explanation questions, and assign a Communications in Mathematics grade out of a total of 6 points. (If a kid shows a lot of appropriate work throughout the quiz but fails to complete the explanation question, for example, I see that as a 3 out of 6.) This means that a kid could have missed some concepts on the quiz, but if they are really good about explaining what they did and showing every step of the work, they are earning credit toward a different assessment criterion. This I like, because it shows an emphasis toward the process used, as well as the final result.
As from last year, I continue to offer opportunities for students to revise their graded work and to re-submit for points. This year, I'm even more generous - they can revise even their project writeups, since my classes are smaller and I can handle the extra grading/feedback workload. And my new perspective is that the quiz process is truly three parts: 1. pre-quiz practice (ie. practice quizzes, done in class), 2. the quiz itself, returned with copious written feedback but not a score, 3. the kid revises the quiz, comes to explain every question to me. I used to think that the last step was optional, but this year my opinions on that have changed, under the new MYP grading system. Under the new grading system, I expect my MYP kids to do this revision step, and it counts towards their "Reflections in Mathematics" grade (as well as bumps up their original quiz score). I think of Reflections in Mathematics as a grade I am assigning towards meta-cognition in mathematics, if you will. I will take a similar approach with projects that are returned, by asking kids to take a close look at a rubric and to pick out specific things they need to work on the next time in order to show improved mastery.
Another thing that I am trying is to introduce formal structure for mathematical lab writeup as soon as possible. I don't quite think my seventh graders are ready for it yet, but by 8th and 9th grade, the students should be doing at LEAST 2 or 3 formal lab writeups a year, complete with intro, plan, data analysis and prediction, and final error analysis. This is because at the end of Grade 11, as part of their IB curriculum, they are supposed to do an "internal assessment" of this form, and I think if we leave it until 11th grade for the teacher to tackle this idea of a formal writeup in math, that is way too late.
So, to that end, I took the formal Grade 11 lab writeup rubric from the IB program and I modified it into a more kid-friendly language for use with younger students. You are welcome to take a look! The first trial run of this lab writeup I am doing is with the cup-stacking activity from Dan Meyer. My (low) Grade 9 group has been working on the rough draft of this writeup in class so that they can ask me for help. Some of them were pretty disorganized and had already lost their data from before, so I let them re-measure the data and explain the steps to me to ensure that they understand what they're doing. It's a very worthwhile process, and I think that forcing them to do this lab writeup has truly enhanced every kid's understanding of the activity. Even from my English language-learners in class, I have seen much more understanding be articulated than I could have hoped for, even within the rough drafts. It's great!
Here are some files that might be useful, if you're thinking about doing this kind of thing: lab writeup checklist and the modeling rubric. They are works in progress, but I figured they're a good starting point.