This has been bothering me for a while, but a few things have come together to motivate me to do something.
Finding the answer on the first page is not a bounce, for example a recent Google search for "is [a red widget] a true [widget]" got a page on my site as the top result, and the content on that page starts "[a red widget] is not a true [widget] because it does not .."
As far as I can find out most analytics (whether log file, self hosted, or third party) would count any one age visit as a bounce. The exceptions are Google Analytics (which lets you define a bounce based on events) and Clicky (which countts one page visits of under 30 seconds as bounces). Are there any other options? What definition should we use for SEO? Which one for distinguishing "unsatisfactory" from "found answer"?