Here's how grading works in my sophomore level chemistry class that is flipped for mastery.
1. Name your assignments by skills you expect students to master. For instance, "Write names and formulas of acids"
2. Use your traditional lesson plan to assign due dates for these skills. The above skill was taught in the 2nd quarter, so I mark it's due date as the day my students would have normally turned in the homework and shown me that they understand how to name acids.
3. Apply the 1-4 scale from SBG to describe whether a student is 1 - not meeting the standard, 2 - progressing towards the standard, 3 - meeting the standard, 4 - exceeding (in my view, consistently and accurately demonstrating the skill). A zero, 0, is assigned if the due date has passed and they still haven't done ANY work at all on it. There may be a lot of these and it is up to you to decide if and when to differentiate your pace and to effectively communicate with parents when you modify your schedule to accommodate for a slower learner (not a slacker).
4. I set up a category called "Weekly Progress." This grade is weighted to be equal in its impact to the unit test grades. Every week I deactivate previous week's progress grades and unit test scores (it takes just a click to do this) so that all I see are the 1-4 scores on each skill and 0s for falling behind. The average at that point in time becomes their weekly progress grade. Then I reactivate everything else so their grade reflects both progress and mastery. While the scores of 0-4 can change at any time, the weekly progress grade is something they can't undo or retake. Either you did your work that week or you didn't.
5. Prepare extra units for students who work ahead. I got approval for an honors designation for students who meet certain requirements, including extra "fun" units of study (which are helpful to those headed towards AP Chem), community service hours (we partner with CoolScience to work at their shows), and extra labs. Even if they don't meet all the requirements for honors, I still have great chemistry lessons for those who work ahead to keep them challenged, interested, and engaged.
I've attached screenshots from Infinite Campus below.
A few more tips:
Stop grading everything! My answer keys are available to students at all times -- I would rather them check their work after three problems and catch mistakes than do ten problems wrong and learn bad habits! Know which problems on your assignments are the ones that best indicate mastery and look for those first. That way if a students says they are "done" with something, you can see if they learned it. Distinguish between doing and learning! For those who copy from their friends (or from my answer keys), pick a question, change the numbers or compounds and ask them to solve it in front of you. I usually ask them to complete the ODD problems so that I can test their understanding or show them examples using the EVENS. They catch on quickly that it's easier to do the work it takes to learn the content than to just fill in answers and try to check off assignments with me without understanding. The more you let the student self-evaluate, the more you develop a sense of responsibility, accomplishment, and self-awareness in your learners. This is powerful. You need to be free to interact with your students and you won't be if you are the one checking every answer on every assignment. Fire yourself from being the grader -- you're the teacher!
Labs: I keep labs out for several weeks, but at some point, we have to neutralize and clean up to make room for other labs. I make an announcement that they have until Friday to do the lab, even if they're not in that unit yet, and then it's gone and they have to watch it on a video (which my students are glad to help me film) and interview a classmate to complete the response sheet or write up. We require a formal lab report once or twice per quarter. Grading six or eight at a time is way easier for me than everyone turning them in on the same day! I also have coworkers who keep different labs set up in their rooms and kids go between our classes to do whatever they need to do, whenever they need to do it. It works for us and I like that we've established that kind of culture.
Falling Behind: Many of those who are behind respond well when you contact parents. Many of them start working feverishly at the end of the semester. Some who were still in unit 2 in the fall semester completed the review and watched all the podcasts they could (they told me this later) and managed to pass the final that was over 5 units... but then they started the second semester exactly where they left off in the first. So even though they were pretty far behind, many have caught up to the pace now. Those who don't may have to sign up for chemistry again next year and will be expected to complete the units they did not master the first time around. I let them know that I will still love them no matter how long it takes them to graduate. ( : But they know that I actually mean it because I get to know them while they're in my class and communicate my belief in them and in their value constantly.
I know this is a lot, but I wanted to be sure to answer your questions. Hope this helps!