Mark Blumenthal and Natalie Jackson of Huffpost Pollster write: If you read polls in the news, you’re probably familiar with the term “margin of error.” What ...
PROC SURVEYSELECT provides a variety of methods for selecting probability-based random samples. With probability sampling, each unit in the survey population has a known, positive probablity of ...
Greg DePersio has 13+ years of professional experience in sales and SEO and 3+ years as a writer and editor. Robert Kelly is managing director of XTS Energy LLC, and has more than three decades of ...