Rtee,
Students often feel that extra credit is awarded arbitrarily, and grading is subjective, so in a way, they may feel it's unfair. I would just say if extra credit is an acceptable practice, it should outlined beforehand, and the criteria for awarding assigned. That way, all students have the same opportunity to utilize it if they wish, and everyone knows exactly how it will be graded, and what contribution to their grade extra credit will supply.
Barry Westling
