On grading
Much of what I think matters in the class is difficult to score--solving the myriad problems one faces when designing and running an experiment designed by you to test your claim is a big value of a lab exercise, but rarely gets assessed. I tend to give out a lot of Error-O-Meter points during labs for this reason.
I think (though I have yet to develop sufficient evidence) that many, perhaps most, students would fare better if they did not have to worry about grades.
Most graded quiz and test items are negotiable--if you provide sufficient evidence that your answer makes sense for a particular problem (or evidence that the question was crafted badly), I may either credit you or drop the denominator by the value of the question. For instance, if it's a 2 point question on a 20 point quiz, I will now make the quiz worth 18 points overall, but let you keep whatever points you earned on the quiz.
(If I realize that a question is not fair before I hand back results, I may just drop the question and adjust the scale accordingly.)
On grade entry
I make mistakes occasionally--we all do. That's why I'd like you to check your grades regularly.
If I make a mistake and give you an erroneously low mark, free to point it out, and I will fix it, provided you have the evidence. (If you toss out your quiz before reviewing the grade, you've tossed away your evidence.)
If I make a mistake in your favor, feel free to point it out, but you get to keep the grade, provided you mention it before I catch the error. Really.
On grade categories
The categories and their weights are set by administration.
Summative assessment (70%)
Test/quizzes/CERs/Errorometer
Student work (15%)
Includes both classwork and homework
Participation/Performance (15%)
This is an administrative category and is not based on student work--all students in my classes receive 100% for this category
This is again an unusual year--grades can be stressful even in a normal year. If you have any concerns about how a grade was determined, please let me know.