Frequently Asked Questions Some General Questions Why am I never called to be polled? You have roughly the same chance of being called as anyone else living in the United States who has a telephone. This chance, however, is only about 1 in 154,000 for a typical survey by the Pew Research Center for the People & the Press. To obtain that rough estimate, we divide the current adult population of the U.S. (about 235 million) by the typical sample size of our polls (usually around 1,500 people). Telephone numbers for Pew Research Center polls are generated through a process that attempts to give every household in the population a known chance of being included. Of course, if you don't have a telephone at all (about 2% of households), then you have no chance of being included in our telephone surveys. Once we've completed a survey, we adjust the data to correct for the fact that some individuals (e.g., those with both a cell phone and a landline) have a greater chance of being included than others. For more on how that's done, see the discussion of weighting in our detailed methodology statement . Can I volunteer to be polled? While we appreciate people who want to participate, we can't base our polls on volunteers. A survey of volunteers is a "non-probability sample" and the results cannot be generalized to the public as a whole. The key to survey research is to have a random sample so that every type