Pew Research Center’s cross-national studies are fielded in a range of polling environments, from countries where telephone surveys are regularly administered to nations where face-to-face surveys are ...

Pew Research Center designed this study to assess the current state of online survey sampling methods – both probability-based and opt-in – and determine their accuracy on general population estimates ...

Stratified random sampling - random samples are taken from within certain categories. Stratified systematic sampling - regular samples are taken from within certain categories.

New York – June, 2021 – Reign Maker, a drone and data services innovation company, today announced the launch of Nixie, the world’s first drone-enabled water sampling and data collection system, ...

Data often comes in the form of numbers.