Quote:
Originally Posted by Devils'Advocate
I try not to agree with Rerun.
All I am saying is that unless a polling company is scrupulous in their methodology, there will be biases and not a true random sampling. I do know that almost all polling companies oversample older people and under sample parents of school aged children and young people. Why? Because older people are the most likely to answer a random call out of the phone book. Younger people either don't have a number in the phone book or they are not at home to answer it. So knowing that there are biases, some of which can be identified and some we don't even think of, we have to take polls with a grain of salt. They can show trends and can give ballpark numbers, but don't expect exact predictions. If they were to follow our methodology, they would be too expensive to run. Rerun *could* be right. He might not be. But sampling size increases would only get you MORE elderly people with land lines. When your sample is not truly random, no matter what your sample size, biases of all kind can take place.
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This is a great post. I'd only add that the sampling errors you've described would be unlikely to import an anti-Conservative bias into the polls, and demographically would more probably lead to over sampling of groups that are historically likelier to be Harper voters.
With that said, there may well be other sources of error at issue here.