DavidS
Anti-Tea Party Member
Conservatives beware - Nate Silver (FiveThirtyEight.com: Electoral Projections Done Right) rips Zogby a new one.
Now, a lot of you have read my analysis on the polls and my strong defense of them. Many of you have also read how much I dislike the Zogby poll - not because he's partisan like GWU/Underground and Strategic Vision, but because his polls don't show any consistency whatsoever for more than 2-3 day period. One day McCain's up 2, the next Obama's by 7.
To use a metaphor, I minored in meteorology and studied the computer models (GFS, EURO, NAM, GFDL, JAM, NOGAPS, etc.). Weather models tend to give you information about weather up to 16 days (384 hours). Let's say I were to see a giant hurricane hitting North Carolina in 16 days from now on the GFS model. I'd make a note of it and look for it on the computer models to see if this model is catching onto something. If I see it on some of the other models, let's say 50%, for a period of time of 5 days or greater, then we have a trend and it's time to look for physical evidence to support this... i.e. sattelite maps.
So to are polls. If one poll, such as Pew, shows Obama up by 15, that to me is a massive hurricane about to hit NC. If none of the other polls show it, I make a note of it and look for a trend for a few days to see if the computer model is still picking it up. If not, then it was a blip. Ground noise. I mentioned the NOGAPS, because it is one of the most unreliabale outlier models in the country. It shows me blizzards in Miami because it's overdoing the amount of cold air that's being pushed down from a canadian high pressure system.
SO! What does this have to do with Zogby? Zogby is like the NOGAPS. It's all over the place. It's not showing me any consistency whatsoever. In addition, here is what Nate Silver, who specializes in these kinds of things says:
FiveThirtyEight.com: Electoral Projections Done Right: Trick or Treat
Now, a lot of you have read my analysis on the polls and my strong defense of them. Many of you have also read how much I dislike the Zogby poll - not because he's partisan like GWU/Underground and Strategic Vision, but because his polls don't show any consistency whatsoever for more than 2-3 day period. One day McCain's up 2, the next Obama's by 7.
To use a metaphor, I minored in meteorology and studied the computer models (GFS, EURO, NAM, GFDL, JAM, NOGAPS, etc.). Weather models tend to give you information about weather up to 16 days (384 hours). Let's say I were to see a giant hurricane hitting North Carolina in 16 days from now on the GFS model. I'd make a note of it and look for it on the computer models to see if this model is catching onto something. If I see it on some of the other models, let's say 50%, for a period of time of 5 days or greater, then we have a trend and it's time to look for physical evidence to support this... i.e. sattelite maps.
So to are polls. If one poll, such as Pew, shows Obama up by 15, that to me is a massive hurricane about to hit NC. If none of the other polls show it, I make a note of it and look for a trend for a few days to see if the computer model is still picking it up. If not, then it was a blip. Ground noise. I mentioned the NOGAPS, because it is one of the most unreliabale outlier models in the country. It shows me blizzards in Miami because it's overdoing the amount of cold air that's being pushed down from a canadian high pressure system.
SO! What does this have to do with Zogby? Zogby is like the NOGAPS. It's all over the place. It's not showing me any consistency whatsoever. In addition, here is what Nate Silver, who specializes in these kinds of things says:
FiveThirtyEight.com: Electoral Projections Done Right: Trick or Treat
Trick or Treat
Do you spook easily?
Judging by the response in my inbox, some of you do.
Matt Drudge is touting the results of a one-day sample in a Zogby poll, which apparently showed John McCain ahead by 1 point.
There are a couple of significant problems with this.
Firstly, there is a reason that pollsters include multiple days of interviewing in their tracking polls; a one-day sample is extremely volatile, and have very high margins for error.
Secondly, the Zogby polls have been particularly volatile, because he uses nonsensical party ID weightings, which mean that his weighting process involves making numbers doing naughty things that they usually don't like to do.
Thirdly, Zogby polls are generally a lagging rather than a leading indicator. This is because he splits his interviewing period over two days; most of the interviews that were conducted in this sample took place on Thursday night, with a few this afternoon. The reason this is significant is because lots of other pollsters were in the field on Thursday night, and most of them evidently showed good numbers for Obama, as he improved his standing in 6 of the 7 non-Zogby trackers.
Finally, there was no favorable news for McCain to drive these numbers. Polls don't move without a reason (or at least they don't move much).
So go out to your Halloween parties and enjoy yourself, and we'll be back to covering the polls for you tomorrow.