Why do pollsters make such a big deal about probability sampling? You'd think that choosing people to interview should be easy. Take three of these, four of those, and two of the other. But it's not.

Investopedia contributors come from a range of backgrounds, and over 25 years there have been thousands of expert writers and editors who have contributed. Thomas J. Brock is a CFA and CPA with more ...

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 ...