I am close to an academic who is facing heavy criticism for having used an unorthodox grading scheme in a final exams (there was a multiplication involved to ensure a good grade would mean decent success in two independent parts).
My main question is:
Q0: what are the main guiding principles you use when designing a test and a grading scheme? Are there any clear limitations imposed to you (legal, moral, or traditional; internal or external)?
Let us assume that the tests handed out are completely anonymous, so that it is given that the grading only depends on the test handed out, and on no other element. In particular, of course discrimination by gender or race or religious beliefs is not acceptable, but no need to mention it since (proper) anonymity should prevent it.
I would also like to gather a diverse array of ways to test and to grade. This type of "big list" question is sometimes seen at MathOverflow, I don't know if it is welcome here but I think seeing a variety of grading scheme and exam designs would help inform the answers to Q0.
Q1: What kind of exam design and grading scheme did you actually use (or enforce if you did not grade but coordinated graders)? What are the motivation behind this choice, and what did you conclude from the outcome? Multiple answers for various pairs of exam design/grading scheme is better unless they directly benefit from being gathered.
It is been asked in comment to specify, so let me add that I am more interested by scientific fields. The question clearly makes sense more generally, but is already quite broad.