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 ...

Learn the distinctions between simple and stratified random sampling. Understand how researchers use these methods to accurately represent data populations.

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 ...

Part One: The nature and process of social research ; Social research strategies ; Research designs ; Planning a research project and formulating research questions ; Getting started: Reviewing the ...