I learned about standards-based grading from the best. This blog post is my take on how to do SBG in AP Physics C. My APC students took AP Physics 1 and AP Physics 2 as a double-period, year-long course as juniors. They're taking APC as seniors—first semester Mechanics, second semester Electricity & Magnetism. This class is about taking the models we learned with algebra and making them more powerful.
I use a scale of Mastery, Proficient, Approaching, and Beginning. Mastery is NOT perfection; the problems in AP Physics C are often too difficult for 97% of APC students to solve in such a short amount of time without talking to other students. I ask difficult questions that I don't expect students to get 100% right. Mastery means that the student understood the problem, used the correct model, and was on the right track. Most of the time, when I have the time, I have students check their own work and assess themselves against the standards. They are usually a little bit harsher than I would be, but I've learned to believe them when they say they deserve a "beginning."
My standards come from reading the AP Physics C Course Description. My standards are focused on the AP Exam even if my teaching isn't always focused. Here are my standards: