Short Read | Aug 6, 2018
What are nonprobability surveys?

Many online surveys are conducted using “nonprobability” or “opt-in” samples, which are generally easier and cheaper to conduct. In our latest Methods 101 video, we explore some of the features of nonprobability surveys and how they differ from traditional probability-based polls.

Report | Jul 5, 2018
How Does Pew Research Center Measure the Religious Composition of the U.S.? Answers to Frequently Asked Questions

Question 1: Measuring religious identity How does Pew Research Center measure the religious identity of survey respondents and the religious composition of the U.S.? Answer: Generally, we rely on respondents’ self-identification.  A key question we ask in many surveys is: “What is your present religion, if any? Are you Protestant, Roman Catholic, Mormon, Orthodox such […]

Report | Jan 26, 2018
For Weighting Online Opt-In Samples, What Matters Most?

A growing share of polling is conducted with online opt-in, or nonprobability, samples. This trend has raised some concern within the industry because, while low participation rates pose a challenge for all surveys, the online opt-in variety face additional hurdles.

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