Originally posted by: shira
Originally posted by: ShadesOfGrey
Originally posted by: shira
Originally posted by: ShadesOfGrey
When cBS weighted the poll for their typical stuff, they didn't consider party affiliation. What that did was weigh out more Republicans because of their other demographic stats.
Something you don't seem to understand is that in any random poll the profile of the polled group will inevitably NOT match the profile of the general population.
For example, if CBS had weighted responders so that 35% were Republicans, they might have ended up with much too high a percentage of evangelicals, whites, the high-school educated, and/or those living in the South (as compared with the general population), and that might have led to results that are less accurate than those actually obtained. ANY deviation in the polled group from the population they're intended to represent skews results.
You seem to be implying that the deviation of the percentage of Republications in the actual, weighted poll group from that in the general population is due to some insidious CBS agenda intended to skew results in some anti-Bush way. But unless you have a deep understanding as to how the weighting process was in fact performed and what its assumptions were, I don't see how you can come to any valid conclusions about motives.
Breakdown by party affiliation is just one demographic out of many, all of which correlate with political beliefs. And the actual weighting used in this CBS poll might well be the very best structuring of the polled group to match the general population.
Exactly, you say they could have oversampled "evangelicals" - or they might have undersampled them. It wasn't part of their weighing scheme. However they do use age, sex, race and others -but when their poll is specifically about POLITICAL opinions, don't you think it might just make sense to weigh for political affiliation just like if they were polling on religion - they should make sure their sample accurately reflects the overal breakdown of religious affiliation in the country?
The only thing I'm contending is that cBS has used a flawed demographic to get their story. They know their sample is flawed, or would if they even looked at the raw numbers so for them to write the story anyway without correcting for the flaw - it's intent is obvious- -unless of course you believe that cBS too incompetent to know better.
No, the actual weighing used could not be the best since it ignored a clear and very important demographic stat - political affiliation.
The main objective of this and most other polls is to assess the OVERALL level of approval/disapproval of the President. Understanding the component percentages is a secondary objective. The two objectives are at odds, unless you use a VERY large sample.
Note that even had CBS polled 39% Dems, 35% Repubs, and 26% Indies, the component results (for example, that 77% of Republicans approve of Bush) might well have been LESS accurate that the ones we're seeing here, since within "Republicans" there's also a complex demographic mix. And unless the "mix" at all levels is close to the actual percentages in the general poplulation, the results obtained will be skewed. So pollsters have to carefully weight their samples to achieve the best possible numbers from a sample group that unavoidably is NOT fully representive of the general population.
Suppose, for example, that there were 350 Republicans (about 35%) in the group originally chosen. But suppose that 40% of that 350 was evangelical Christians, whereas the actual percentage Republicans that are evangelicals is 30% (I'm making these numbers up, but the point remains the same). If one wished to get a more accurate idea of what Republicans believe about Bush, then one would want to randomly reduce the number of evangelicals in the Republican group by 35. That would help to get a more accurate result for Republicans, and also might help the accuracy of the overall result. But note that a consequence of this reduction is that the percentage of Republicans in the poll would be below 35%.
The point is, the objective of any poll is to obtain meaningful results, not to blindly choose a percentage of this polical group and a percentage of that, and assume that the results (absent weighting) will be acccurate.