Why Advisers with an 'E'?

When I was trying to think of some witty thing to title this blog, one of the first things to come to my mind was "adviser." The word "adviser" fits in that I'm hoping this blog functions in some ways in an advisory capacity, both between the copy editors and between the copy desk and everybody else, but the truth of the matter is that the Associated Press style on "adviser" has been a source of constant puzzlement to me.

The Associated Press standard is to spell the word "adviser," according to my stylebook. Colloquially, I've always seen the word spelled as "advisor" (although looking now at dictionary.com, it's spelled both ways). But the rule is inconsistent; "advisor" can be spelled "adviser" (based, presumably, on the word "advise"), but "supervisor" is never spelled as "superviser" if we apply that same rule. The Associated Press spells the word "supervisor," presumably; there's no entry in my stylebook that it should be spelled any other way. So in my mind, it's a weird idiosyncrasy that a word should be spelled one way but a similar word spelled a different way.  And further, we call it an "advisory," not an "advisery," adding a whole new weird dimension to the usage.  (apstylebook.com's "Ask the Editor" feature is strangely silent on why "adviser" and not "advisor.")

These are the strange things I think about.  And so we hope to similarly get you thinking.

-Benton