<p>I think that most students don’t report it. Except perhaps at colleges with honor codes, they are under no obligation to do so. They’re also under no obligation to go over the corrected test in detail, which is the only way in which they would discover the discrepancy. So it’s not like they’re going to get in trouble for not reporting it.</p>
<p>Are they doing the ideal thing, ethically? No. But we live in the real world.</p>
<p>How many students really look at an exam once it’s returned, other than to take note of the grade? I realize that grading errors aren’t unusual. Probably the people most likely to review the scoring are disappointed students trying to find a grading error in the other direction. In which case, of course, they’d be more disappointed to see that the true score was lower than the original.</p>
<p>Are they obligated to report it? Well, as Marian says, probably in a perfect world.</p>
<p>I would–and have–reported it, but I have a very guilty conscious and I like to sleep at night. Interestingly, however, I’ve never had a teacher or professor take away the points, although they’ll usually say they appreciate the honesty,</p>
<p>I agree with marian regarding honor codes. My institution’s honor code would suggest that reporting an error is required; otherwise, the student is getting an unfair advantage. I once had a student report a large error in his favor. When the TA was toting up the points on an exam he gave the student 20 points extra. I was impressed that the student reported it to me. After deciding how to deal with the case, I polled several colleagues to ask what they would have done. We all went for the same compromise: give the student half of the points.</p>