New post - Josh Marshall - "What Do The Polls Tell Us"? Long, good read.

[NRaleighLiberal]

http://talkingpointsmemo.com/archives/2012/10/what_do_the_polls_tell_us.php

"With 9 days to go before election day, I thought I’d take a moment to go over where the polls are as of today and what if anything they can tell us about what the headlines will be on November 7th.

If you’re a polling or data diehard a good bit of what follows may seem obvious. But not everyone’s a data nerd. So I want to go through a lot of data points and basic questions we get in one go. So here goes.

NATIONAL VOTE

Clearly, we’re going to have a very tight outcome in terms of the national popular vote. With the exception of two extreme outliers — Gallup and Rand — all the national tracking polls show a race that is either tied or within 1-3 points. You can see the latest here.

So why is there such a variance? It’s worth noting that in statistical terms this isn’t that big a variance. There is an inevitable amount of noise in all polling data. But if you look at the tracking polls individually you’ll note that they’re actually not bouncing around that much at all. Among other things that points to the conclusion that more than noise the difference here is likely voting models — how many people and which people are actually going to show up. So for instance, you’ll note that Gallup currently has Mitt Romney up by 4 percentage points among likely voters but has Obama beating Romney by 1 point among registered voters. Pollsters are making different bets about the scope of voter turnout and just which groups are going to show up."

snip

goes over OH and VA in detail, makes some prelim conclusions