report | Sep 7, 2023

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.

report | Apr 19, 2023

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.

report | Aug 25, 2021

How Call-In Options Affect Address-Based Web Surveys

One method to improve survey representation of the non-internet and less literate population is to allow people to take surveys offline. In March, we fielded a study to test the feasibility and effect of collecting data through respondent-initiated interactive voice response; here’s what we found.

report | Jun 9, 2021

Measuring the Risks of Panel Conditioning in Survey Research

A new evaluation of the Center's national American Trends Panel finds little evidence that panel estimates are affected by errors associated with panel conditioning, a phenomenon that occurs when survey participation changes respondents’ true or reported behavior over time.

report | May 3, 2021

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.

report | Apr 8, 2021

Confronting 2016 and 2020 Polling Limitations

Looking at final estimates of the outcome of the 2020 U.S. presidential race, 93% of national polls overstated the Democratic candidate’s support among voters, while nearly as many (88%) did so in 2016.

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