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 ...

Will Kenton is an expert on the economy and investing laws and regulations. He previously held senior editorial roles at Investopedia and Kapitall Wire and holds a MA in Economics from The New School ...

Considerable controversy has taken place between those who favor quota sampling and those who advocate area sampling in opinion polling. This article does not attempt to give a final solution to the ...

Abstract: Understanding the composition and fluxes of vadose zone soil water is extremely important to many environmental studies, and hence the monitoring of soil solution is of basic interest for ...