I'm confused as hell and don't know WTF they're doing.
http://www.realclearpolitics.com/epolls/2008/president/us/general_election_mccain_vs_obama-225.htmlThey are including one set of numbers derived from the daily Gallup polling, as a separate poll (labelled "Gallup Tracking"). This is an interpretation of the Gallup Daily Results (averaging the 2 LV scenarios), and RCP, at least, is pretty clear on that.
Then there's another "separate" poll, also averaged in their "RCP Poll Average", which appears to be another interpretation of the same data (labelled "USAToday/Gallup*"), though they're not as clear on how they derived that one. You jump to the link of the first one, and RCP explains themselves. You jump to the link for the 2nd, and you get a USAToday page that explains nothing. I have no idea how they got that number. It's obviously an average, but it doesn't work if you just average the 2 LV and the RV numbers.
What is clear, though, is that RCP is treating one poll as two. And they seem to be planning on doing this every day, tilting the average to whatever Gallup results show. Gallup's info appears to indicate that these LV's are just a subset of the RVs. But even if they were not, the 2nd poll included in the RCP average is NOT simply the RV poll.
So Gallup is now releasing 3 polls a day (or 3 interpretations of the same polling data: RV, LVI and LVII). Fine, if they want to. But if you're a polling site keeping track of a "poll average", I'd think you just use one of those by some consistent criteria. And for RCP, that would be the one they have been using all along for the Gallup Daily: RV.
UPON FURTHER READING, RCP says (in the link from the "Gallup Tracking" poll, then linked to "for more explanation" at the bottom): "In order to not double count the Gallup Daily Tracking poll survey results in the RCP National Poll Average", they are averaging the two LV scenarios. BUT THEN they STILL include this LV average, AND a second version of the Gallup Daily numbers!