Survey Methods

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.

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.

Polling organizations have taken close looks at how election surveys are designed, administered and analyzed. We are no exception.

Given the errors in 2016 and 2020 election polling, how much should we trust polls that attempt to measure opinions on issues?

The 9-point fall in approval was the largest change between two Pew Research Center polls since Donald Trump took office.

Since the establishment of the ATP, the Center has gradually migrated away from telephone polling and toward online survey administration, and since early 2019, the Center has conducted most of its U.S. polling on the ATP. This shift has major implications for the way the Center measures trends in American religion – including those from the Center’s flagship Religious Landscape Studies, which were conducted by phone in 2007 and 2014.

Eight-in-ten Americans say they don’t generally answer their cellphone when an unknown number calls, our survey found.

As news outlets morph and multiply, both surveys and passive data collection tools face challenges.

Many who follow polls are asking how these errors could happen. Here, we’ll take a preliminary shot at answering that question.

Data tables from interviews we conducted with verified voters after the 2016 and 2018 elections may help answer some election 2020 questions.