Becky Hirta's recent post about grades got me thinking. My college doesn't give 'plus' or 'minus' semester grades -- you can get a B, but not a B-plus or a B-minus. The topic comes up for discussion about once a year. The argument for pluses and minuses is basically that they offer greater precision. There's some distance between a B-plus and a B-minus, but in our system, that difference is erased. By the same token, if a student is on the border between two letters, there's more at stake in the decision which way to go.