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 ...

The analysis in this report is based mostly on a survey conducted November 12-21, 2014 among a sample of 1,835 adults (921 women and 914 men) 18 years of age or older. The survey was conducted by the ...

Systematic sampling is straightforward and low risk, offering better control. However, it may introduce sampling errors and ...

With a population of over 40 million users worldwide, a number doubling every year, the internet has become a medium with distinct business opportunities. To academic and commercial researchers, the ...

Collectively, recreational fisheries can take a significant fraction of the yearly catch—in some cases more than commercial fisheries. It is important that systems used to monitor fishing catch are ...

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 ...