This got a bit lost in the excitement over my first question, (k+1)th or (k+1)st?, so I thought I'd spin it off into its own question. I'm not sure if this is too abstract to be appropriate for this venue, but I thought I'd give it a shot.
When trying to figure out which of two variants of the same phrase is more common, a good first step is to Google both (putting each in quotation marks) and seeing how many hits each garners. As we discovered in my other question, this fails when one or more of the variants contains punctuation. You'd be out of luck if you wanted to decide whether to put a hyphen in full time: "full time" and "full-time" give exactly the same search results, even with quotation marks. (The situation is a bit more complicated with "(k+1)st", but the bottom line is that it returns many results which don't contain the literal string I was searching for.)
Is there any way to measure how widely a phrase with a specific punctuation is used?
Note that this is question is about measuring usage, not deciding what variant is best for a given situation. For that, the best way is presumably to ask a question here :)