A simple random sample is a subset of a statistical population where each member of the population is equally likely to be ...

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 ...

Bees (family: Apidae) are important ecologically and economically as primary pollinators of many natural and agricultural systems. Given current concerns about declining numbers of bees, many ...

Here at Pew Research Center, we are often asked about how we conduct our research. We work hard to make our methodologies transparent and understandable, but we also know that survey mode effects and ...