Use of weighting edge by political parties in polls....

[whistle]

...I actually posted this on another thread, but I think it is important enough to prompt a thread of its own to get some qualified answers from DUers who know about this stuff. Here it is.

I'm a little slow when it comes to conceptualizing number proportions that are used and reported in national polls. As memory serves me, in the 2000 presidential election, ignoring the votes which Gore failed to receive because of fraud, trickery, miscounting and the U.S. Supreme Court intervention, the popular vote counts were something in the nature of:

Gore....50.9 million
Bush....50.4 million
Nader... 3.9 million
Other... .4 million

Our man Gore certainly would have won Florida and the electoral college vote and been president had he been allowed the 517 or 527 votes that the Supreme Court denied. But let's just set that aside and use the popular vote advantage that Gore got which was approximately a half million more votes than Bush got. I fully understand that winning the popular vote does not necessarily mean that candidate will win the electoral vote. With me so far?

Now, we get a polling company that does its survey for ease of calculation here, on 1,000 completed interviews of registered voters of which 900 say they are likely to vote on November 2, 2004. Among these 1,000 respondents the idea is to get a proportionate random sample of republicans, democrats and independents to represent the distribution of these three groups of voters across the country.

The polling company has the choice (trade-off) to do a poll perfectly (which takes time and money) or fast (which meets the needs to get their name published ahead of all others), and since they have limited time, staff and resources, the pollsters do the best that they can. I'm trying to be fair here, but as a consumer, I also want to know and understand what goes on with the numbers and polling the process to maintain credibility.

An event occurs, for sake of my illustration here, it's the recent intensity of resistance fighting in Iraq over the latter part of this week, so I as the pollster get my team mobilized to telephone, qualify, screen and interview the 1,000 respondents and I use all of the acceptable procedures and standards of polling and do not cut corners or cheat. We randomize, qualify, monitor the interviewers etc. and in one evening and a day of intense calling we get the 1,000 completes which are immediately processed and reported in the AP before 4:00PM today, so it gets the 6:30 national news coverage, the Sunday papers and all of the Sunday morning political programs like Meet the Press and so forth.

What if anything, does the polling company have to do to the results to make them credible when the reporter says: "A new poll just out by Whistle Research says that John Kerry has inched ahead of President Bush 48% to 46% in a poll released just two hours ago,...blah, blah, blah."

The results to the question: "If the election for president of the U.S. were held today who would you vote for:

George W. Bush (rep)...
John F Kerry (dem).....
Ralph Nader (reform)...
Undecided..............

Where does the weighting come in? What legitimate right does the polling company have to use a weighting? Why are weightings not disclosed if they in fact have a major impact on the results?

[ferg]

1. calibration questions

My understanding (I'm not an expert) is that you ask some calibration questions:

1. Did you vote in 2000?

2. If yes, who did you vote for? Gore/Bush/Nader?

The results to question 2 should be approximately 48% Gore, 48% Bush, 3% Nader.

If the results of question 2 are much different, there's a problem. You either need to report that you have a bogus poll or you need to do something to the poll to make those numbers work out correctly. (For example, you could weight the results to make the calibration results come out right.)

If you get results that are near 48%/48%/3%, then you can be pretty confident that your poll is statistically random.

[whistle]

4. That makes sense, but is that kind of thing disclosed....

...I never hear that reported and when I look at the poll summaries on various site even the ones that the polling companies have, they say nothing about that.

[DemocratSinceBirth]

2. I Think You Weight To Ensure Your Sample Reflects The Potential Electorate

Unless your poll adequately reflects the demographics and party identifications of the actual electorate your poll is worthless....

[Poiuyt]

3. There's a good explaination of the polling process today at

http://www.electoral-vote.com/

[whistle]

5. Good report, good explanation, terrible news!

...I think though the Gallup example shows just how distorted the results can get when the polling base is manipulated. I would rather see Gallup redo their polls to reflect the true distribution that assign arbitrary weights. That just strikes me as so misleading.