Polling

Hi Everyone:

Years ago, I worked in Statistical Methods Division of The United States Census Bureau doing survey design. I still have my finite sampling theory books. And for those who don't know, designing statistical surveys and polling are the same thing.

Today, there are a lot of questions about whether the polls are any good, and if some are good, which ones are those? Now, that's a question I can't answer since I don't know their methodology, but I can answer some general questions about polling that some of you might have. And I'll check this thread everyday to see if there is anything I can answer.

And for starters, here's the first question I'll answer:

Question: Some polls seem to oversample Democrats, does this mean the result will be inaccurate and give the Democrat a higher number than he deserves.

Answer: As long as the weighting of the Democrats is adjusted for the over sampling, it should have no effect on the estimate. What it will do is create a slightly higher variance to be associated with the estimate. So, when you hear or read that the Democrats (or Republicans) are over sampled, you should ignore it.

Best wishes,
Mason