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 ...

This study reports the findings of a comparison between different non-probability sampling methods applied in a WWW-user-survey. This study reports the findings of a comparison between different ...

Stratified random sampling is a method of sampling that divides a population into smaller groups that form the basis of test samples.

The pre-module is a quick reference guide, focusing on the practical steps for conducting a SENS survey. It is not meant to replace already existing survey manuals. To avoid duplication, the user is ...

Exit polls 2026: learn what post-poll surveys are, how they are conducted using sampling methods, legal rules under 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 ...

Melissa Horton is a financial literacy professional. She has 10+ years of experience in the financial services and planning industry. Robert Kelly is managing director of XTS Energy LLC, and has more ...