Our school has a online grade book which we can check our overall grades. I just checked my Art grade, which I was getting 97% before but I don't know why my grade dropped to 93% and next to the overall grade there was a word "Overridden". I don't really know what's Overridden, and also is it bad? Cuz my grade just dropped a lot.

Just saying if this make any differences : We don't have test for art and also I got good grade for every assignments. There are no differences showing up with the assignment grades, but the only difference is the overall grade and the word Overridden showing up.