Hi Sarah:
I might ask if your students have satisfactorily completed their regular assignments, why is there the need for extra credit?
Some teachers may want their students to improve their grades and be tempted to offer EC. But really that only adds points, and contributes very little to learning.
My bias is to avoid EC, because my backgraound is teaching critical care topics. People can be hurt or harmed by mistakes, or worse if students don't get their knowledge and skills perfected.
If it's important enough to award credit, I think it should be part of the regular curriculum.… >>>