This study looks at how national public opinion polling in the United States changed from 2000 to 2022. It focuses on two aspects: the sample source(s) – that is, where the survey takers came from – ...

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 ...

Method comparison studies and statistical agreement analysis are essential for evaluating and validating different measurement techniques across a variety of scientific and clinical disciplines. These ...