Can AI Stand In for Human Survey-Takers? Not Really
Synthetic surveys using digital twins do a poor job estimating the public mood and are especially error-prone for some subgroups, including Republicans and Black adults.
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Our favorite data visualizations of 2025
In this post, we’ll highlight a few of our favorite visuals from 2025 and walk through how we made them and what makes them successful.
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Video: Why have polls underestimated Donald Trump?
We’re in an era where the people most likely to respond to a poll are also the most likely to vote Democratic for president. Pew Research Center’s head methodologist Courtney Kennedy explains how pollsters are tackling this challenge to make samples as representative as possible.
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Counting Race: How the Census Measures Identity and What Americans Think About It
How the U.S. government measures race has changed substantially since censuses began in 1790. Today, Americans differ on whether the government should ask about race.
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The changing categories the U.S. census has used to measure race
Racial categories, which have been on every U.S. census, have changed from decade to decade, reflecting the politics and science of the times.
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Q&A: How Pew Research Center estimates the number of unauthorized immigrants living in the U.S.
In this Q&A, we speak with Senior Demographer Jeffrey S. Passel about how the Center estimates the number of unauthorized immigrants in the U.S.
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How Pew Research Center Uses Its National Public Opinion Reference Survey (NPORS)
In 2020, Pew Research Center launched a new project called the National Public Opinion Reference Survey (NPORS). NPORS is an annual, cross-sectional survey of U.S. adults. Respondents can answer either by paper or online, and they are selected using address-based sampling from the United States Postal Service’s computerized delivery sequence file.
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Behind Trump’s 2024 Victory, a More Racially and Ethnically Diverse Voter Coalition
Pew Research Center’s in-depth study of its survey respondents who voted in the 2024 election examines turnout, voting patterns and demographics.
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Country-Specific Methodology
Detailed information on Pew Research Center international survey methodology, such as mode of interview, sampling design, margin of error, and design effect, for each country we survey, organized by survey, country and year.
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Signature Reports
A Field Guide to Polling: Election 2020 Edition
While survey research in the United States is a year-round undertaking, the public’s focus on polling is never more intense than during the run-up to a presidential election.
Comparing Two Types of Online Survey Samples
Pew Research Center conducted a study to compare the accuracy of six online surveys of U.S. adults – three from probability-based panels and three from opt-in sources. On average, the absolute error on opt-in samples was about twice that of probability-based panels.
Q&A: What is the American Trends Panel, and how has it changed?
Members of the American Trends Panel can now take our surveys online or over the phone with an interviewer.
How Public Polling Has Changed in the 21st Century
A new study found that 61% of national pollsters used different methods in 2022 than in 2016. And last year, 17% of pollsters used multiple methods to sample or interview people – up from 2% in 2016.
