> In Gallup's and CBS's case, we are assuming they are
> following the standard procedures. So why they would both end up with
> such skewed samples is a complete mystery that indicates that something is
> completely out of whack. Either they aren't following the standard
> process, or some new development has thrown a spoke in the standard
> process, or something is wrong with our assumptions.
>
> As for assumptions angle (the only one we can really analyze without more
> information) our prime assumption is that party ID varies in smooth
> continuous trends and doesn't gyrate wildly. Something may have changed
> and maybe it is. But offhand, it doesn't make sense why that would
> suddenly happen this of all elections, because this is the most partisan
> election since 1972, with the highest, earliest interest level and the
> smallest amount of independents and persuadables. Those seem like the
> conditions least conducive to frantic party switching.
The obvious solution is to aggregate the party ID responses from all the recent polls other than Gallup and CBS and then compare them with Gallup/CBS. If an aggregate sample of, say, 10,000 respondents gives a party ID split in the ballpark of the 2000 VNS numbers while Gallup/CBS gives far more Republicans, then you can assume there's something wrong with Gallup/CBS.
The mystery is what could possibly cause Gallup/CBS to get such weird samples. Mathematically it seems impossible.
Seth