Stratified random sampling is a method of sampling that divides a population into smaller groups that form the basis of test samples.

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 ...

Melissa Horton is a financial literacy professional. She has 10+ years of experience in the financial services and planning industry. Robert Kelly is managing director of XTS Energy LLC, and has more ...

The first video in our “Methods 101” series is about random sampling, a concept that undergirds all probability-based survey research. Here’s how it works. Fresh data delivered Saturday mornings Thank ...

Sampling is the process of collecting some data when collecting it all or analyzing it all is unreasonable. Before addressing why sampling still matters when massive amounts of data are available and ...