<p>My school does it by percentiles, with purely UW GPAs. And our valedictorian is calculated via the UW GPA, which I find to be silly. We do narrow it down to one in the end, but someone with a 4.3 W but a 3.9 UW has no chance for valedictorian, even if there are tons of 4.0 UW and 4.0 W's.</p>