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 ...

One possible explanation for the variability in estimates across the different nonprobability samples is the range of methods that online sample vendors employ. They differ on recruitment, weighting ...

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 ...

A simple random sample is a subset of a statistical population where each member of the population is equally likely to be ...

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 ...

Do you know what worms and other hidden creatures are living in your soil? You might be amazed by the diversity and importance of these organisms for your garden. If you'd like to learn more about the ...