Learn about standard error, its role as the standard deviation of a sample, and how it measures the accuracy of a sample ...

It’s in vogue these days to declare the building blocks of statistical inference irrelevant to assessing the performance of schools. For example, Joel Klein recently argued that statistical ...

Sampling error refers to the difference between our survey estimate and what we would have found had we been able to interview everyone in the population. When it is reported, it is described as “plus ...

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

A behind-the-scenes blog about research methods at Pew Research Center. For our latest findings, visit pewresearch.org. Academic survey researchers tend to differ ...