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 researchers increasingly recognize that a single survey of the general public can rarely represent the views of small groups of Americans. Such surveys frequently have too few interviews with ...

Power analyses and sample size calculations are important parts of many research projects. Often, before data are even collected, it is necessary to calculate and justify the required sample size for ...

The alternative text for this image may have been generated using AI. Box 1 Summary of guidelines for destructively sampling herbaria by herbarium users and herbarium stewards Herbarium ...

To develop effective food control systems, regulatory bodies and laboratories in Member States must have the capability to apply sound sampling schemes and analytic methods. Our efforts focus on the ...

It's not feasible to contact every member of the population, so only a sample, or a subset, of that population is included when conducting statistical research. The assumption is that the sample is ...