since she teaches calculus

That will probably help, in fact. This isn't subjective either, it's physical oceanography - which is basically ocean calculus!

I'm beginning to think it is rubric after all. I Googled it, and came up with a bunch of teaching sites. But this use isn't in the dictionary. It does make sense, though, because among its meanings are "authoritative rule", and, as a verb, "to mark up with red" (which is what we're doing).