Low statistical power undermines the purpose of scientific research; it reduces the chance of detecting a true effect. Perhaps less intuitively, low power also reduces the likelihood that a ...

The probability that the null hypothesis will be rejected when it is actually true is called the false positive rate and is determined by the significance level of the test (called alpha which is ...

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 ...

Probability is a measure of the likelihood of events happening. The greater the proportion of times an event can happen the greater (or more likely) the probability. Events can be ordered by the ...

Suggested Citation: "5 Sampling and Estimation." National Academies of Sciences, Engineering, and Medicine. 2018. Reengineering the Census Bureau's Annual Economic Surveys. Washington, DC: The ...