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.

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.

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

While the growth of online interviewing is a prominent trend in polling, there is variation within that trend in how researchers recruit respondents. This study finds that sourcing affects data quality.

How many U.S. adults use the internet? There are a lot of sources with answers to this question. Yet these different sources can be tricky to reconcile.

when designing an online survey questionnaire, there is more than one way to ask a respondent to select which options in a series applies to them.

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.