Hi Pandora:
Ref Extra Credit on exams. I think every teacher and institution has to determine what they think works best for the school and or the the class. Many institutions simply don't allow it. Many teachers won't either, usually freom poor past experiences and the net effect oin student learning.
Now maybe it's semantics, but I think there is a difference in extra credit, where students simply get awarded points for really nothing actually assigned with the purpose of raising a grade. To me, thats not fair.
But say, an essay question on an exam may have a bonus point depending on the correct response, or some teachers will state at the beginning they will drop the lowest quiz score, policies like this give a boost to meritorous students and it's fairly offered to all students - that's something different.
Extra credit is a very controverserial topic with no clear right or wrong answer. It seems to me if the information is important, it should be included in the required assignments with giving away points for really no real work.
Regards, Barry