Note: This report was updated on Dec. 30, 2015 to reflect the January-July 2015 National Health Interview Survey estimates released on December 1, 2015. Telephone surveys face numerous challenges, but ...

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 analysis in this report is based on telephone interviews conducted from Sept. 15 to Oct. 13, 2015, among a nationally representative sample of 1,807 parents, 18 years of age or older, with ...

Targeting matters most. Surveying the wrong audience can lead to misleading data and poor decisions, even if the questions themselves are solid. Weighting shapes reality. Overrepresenting certain ...

SHELTON, Conn., March 15, 2011 /PRNewswire/ -- Survey Sampling International (SSI)—the leading global provider of online and offline sampling solutions—has appointed Chris DeAngelis to head its new ...

Wondering how many people in the United States have a smartphone? If you poll 20 people on the street, your survey won’t be representative of the entire American population. But if you just want to ...

The nuts and bolts of our public opinion surveys. A summary of ABC News' polling standards and survey methodology follows. ABC News maintains standards for disclosure, validity, reliability and ...

We collaborate with the world's leading lawyers to deliver news tailored for you. Sign Up for any (or all) of our 25+ Newsletters. Some states have laws and ethical rules regarding solicitation and ...