In survey research, sampling errors occur because all samples are representative samples: a smaller group that stands in for the whole of your research population. It’s impossible to survey the ...

In the second clip, Caitriona Perry, former Washington Correspondent for RTE, Ireland’s public service broadcaster, talked about polling leading up to the 2016 election and the factors that ...

How do I know if a candidate’s lead is ‘outside the margin of error’? News reports about polling will often say that a candidate’s lead is “outside the margin of error” to indicate that a candidate’s ...

Phone vs. digital polls "The polling industry is going through what I would call a paradigm shift, where we're moving from the types of methods that worked 30, 40 years ago and don't really work ...

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 ...

Yarilet Perez is an experienced multimedia journalist and fact-checker with a Master of Science in Journalism. She has worked in multiple cities covering breaking news, politics, education, and more.