It has been nearly 20 years, but my rule of thumb was that I wouldn't leave until I had done *three* review passes of the test. That is, quadruple checking, completing the exam and then reviewing my answers three times. That is pretty far into the diminishing returns for me catching my own errors.
That *almost* never happens, but there are exceptions -- sometimes they really do give way way more time than you need, especially if you are already strong at the material in question.
With that said, the key point is that the time tradeoff here for leaving early is terrible in typical college classes that have heavy weight on exams. Especially the first 10 -20 minutes of double checking is very likely worth 5+ hours of homework time or study time in terms of points towards the grade.
It has been nearly 20 years, but my rule of thumb was that I wouldn't leave until I had done *three* review passes of the test. That is, quadruple checking, completing the exam and then reviewing my answers three times. That is pretty far into the diminishing returns for me catching my own errors.
That *almost* never happens, but there are exceptions -- sometimes they really do give way way more time than you need, especially if you are already strong at the material in question.
With that said, the key point is that the time tradeoff here for leaving early is terrible in typical college classes that have heavy weight on exams. Especially the first 10 -20 minutes of double checking is very likely worth 5+ hours of homework time or study time in terms of points towards the grade.