Survey sampling and estimation methods form the cornerstone of modern statistical inference, underpinning research across the social, medical, and natural sciences. At their heart, these methods ...

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 ...

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 ...

Non-invasive sampling methods include saliva analysis, hair analysis, urinalysis, and breath testing. <br/>The importance of ...

This is a preview. Log in through your library . Abstract Sampling the density and basal area of trees is fundamental to quantitatively characterizing forests and woodlands. Commonly used sampling ...