If you've ever noticed on specific searches, Google gives you a post count and estimates the number of authors of posts in the snippet like the screenshot below indicates:
But if you ask me, the number there is entirely inaccurate. The question: where does Google get these numbers and how does it calculate them?
That is the question being asked in a Google Webmaster Help thread, where Googler JohnMu promised to look into it. John said:
I'll check up on that & let you all know what I find out :)
When John updates the thread, we will let you know what he says.
Forum discussion at Google Webmaster Help.