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 ...

Learn the steps and see examples of simple random sampling, which ensures each member of a population has an equal chance of ...

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 ...

verybody has a favorite color and season—preferences that seem innate, always defying reason. Auditors are no different when it comes to haphazard sampling, a process in which—ideally—they choose ...

Pew Research Center’s team of demographers, economists and other analysts accesses and uses a wide variety of publicly available data sources to conduct its population research. Much of this data is ...

Building on its legacy of standardizing LC separation, Evosep now extends upstream to sample preparation, delivering complete ...

Nosocomial infections are infections that are acquired while at a health care facility and are not present at the time of admission. Nosocomial infections are many times also called hospital acquired ...