<p>Does it depend on the professor?</p>
<p>Yup, professor decides on the grading scale :)</p>
<p>The popular ones are:</p>
<p>93% for A; 90% for A- for a lot of humanities/social science/lower div anything classes where there isn’t a large skew in a grading curve</p>
<p>The rest: Median + 2stdev (+.5stdev) for A-/A. For example, if there’s an exam (assume normal distribution; bimodal distributions don’t happen too often) with a median of 70 and stdev of 8, 70 + (2<em>8) = 86 for A-; 70 + (2.5</em>8) = 90 for A.</p>
<p>The second isn’t a policy or anything, but most curves fall towards something along those lines, at least by anecdotal experience.</p>
<p>And if there’s a skew left or right (resulting in large stdevs), different methods are used to adjust the curve; either the professor will subjectively make the cutoffs for certain grades, or some log() will be applied to an algorithm to avoid subjective grade adjustments.</p>
<p>many grades are subjective though – as a TA i’ve been able to up grades by a fraction (ie, B+ to A-) by arguing that so-and-so had a really crummy lab partner who was cramping their style, they had to work extra hard, etc. and one class that i was pretty sure i wasn’t going to pass – snuck by with a C-, and i’m pretty sure it’s because i worked for the professor.</p>
<p>it happens. but from what i’ve seen, subjective adjustments can only help the student (otherwise it’s bad news bears if anyone ever finds out a prof actually lowered a grade out of spite).</p>
<p>Whenever I’ve TA’ed, the professor usually just signs the grade form the graduate TA’s make. They really don’t do much in terms of nit-picking individual students’ grades–at least in the social sciences/maths.</p>