Our third Methods 101 video explores some of the ways that nonprobability surveys differ from traditional probability-based polls. How do pollsters conduct surveys online and what does that mean for ...

Survey sampling and estimation methods form the cornerstone of modern statistical inference, underpinning research across the social, medical, and natural sciences. At their heart, these methods ...

The first video in Pew Research Center’s Methods 101 series helps explain random sampling – a concept that lies at the heart of all probability-based survey research – and why it’s important. Fresh ...

A practical method of drawing sampling units with probabilities exactly proportional to size is described, in which both preliminary calculations and the addition of a large number of sizes are ...