CNN's Apparent Weighting Game

Pole Vaulting or Poll Weighting?

Poll Weighting sounds like an Olympic event, doesn't it?

So what does Pole Vaulting have to do with CNN's Poll Weighting?

Keep reading...

Today, CNN is reporting the results of their most recent presidential poll:

Among likely voters (trans. White suburban population):

Kerry 50% Bush 46% (MOE +/- 4%)

Looks like a dead heat.
Bad news for Bush, though. This is his strongest demographic!

But wait.

The survey of likely voters weighted the sample to assume a turnout of 50 percent, consistent with recent presidential elections.

In the current poll, a wider sample of 891 registered voters showed a slightly larger apparent lead for Kerry, but one that was still within the margin of error.

Fifty-one percent said they would vote for Kerry-Edwards, and 44 percent supported Bush-Cheney. LINK

Still within the MOE? 51% - 44%?

What a crock!

From The National Council On Public Polls:

Bad Weighting:
The most common bad weighting in political polls is weighting just the likely voters for the number of Democrats, Republicans and others. Party identification is correlated with voting, but what is missing are meaningful numbers of party members for the whole population. Without that, the weighting is a guessing game rather than good theory. Some pollsters use the numbers from an exit poll from a past election, but the numbers of people who consider themselves members of a party changes from month to month and year to year.

Another type of bad weighting for elections polls occurs when the weighting characteristic has a low correlation with key variables such as voting. For example, in some elections there may be no relationship between age and voting. If the age-voting relationship is weak then weighting for age will make the sampling error larger. Sometimes there is a strong relationship with vote but a weak relationship with some other characteristic. That other characteristic will have a larger sampling error. One also should avoid weighting that creates a large discrepancy in the weights applied to different sample cases. LINK

Hey, CNN! Your motive is showing!
My Favorite part of the bogus CNN poll report:

A previous poll, conducted June 21-23, found Bush barely leading Kerry, 48-47. Bush had led Kerry as much as 55-43 in similar polls going back to early January.

This Pole Vaulting graphic does a better job describing CNN's current poll results!
(Substitute Kerry for 1980 and Bush for 1960 on the graph.)


Kerry-Edwards (1980) v Bush-Cheney (1960) 
So what have we learned today, class?

1. Kerry-Edwards currently leads Bush-Cheney 51% to 44%.
2. CNN favors Bush-Cheney.
3. CNN will do anything to prop up Bush-Cheney, including reporting 7 month old polling data (which now also looks specious).
4. CNN wants you to think that Bush is wildly popular, even after he's jeopardized the country and the planet.
5. CNN lies.

Contact CNN...

Tell CNN they'd be better off covering Pole Vaulting this Summer!