Methodological Research

Pew Research Center makes most of its datasets available for download once reporting has been completed for a given study. Here's how to find and access our data.

The 2020 census counted 126.8 million occupied households, representing 9% growth over the 116.7 million households counted in the 2010 census.

If you’ve wondered what opinion polls are for, how they are done or how to tell a good one from a bad one, sign up for our email mini-course.

Public polling estimates on COVID-19 vaccination have been within about 2.8 points, on average, of the CDC's calculated rate.

Since the initial disruptions of field operations due to COVID-19, we have been able to conduct 33 surveys in 17 countries and territories.

Here, we address some of the most common questions we receive about the nuts and bolts of taking a U.S.-focused Pew Research Center poll.

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.

Here, we discuss the findings of a comprehensive report about the polling errors of 2020 and their implications for polling.

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.

The difference in support for the death penalty by survey mode has important consequences for understanding trends on the issue.