Sampling error, however, is oversimplified when presented as a single number in reports that may include subgroups, poll-to-poll changes, lopsided margins and results measured on the difference ...

The potential degree of this error in a particular poll is reflected in the margin of sampling error, a measurement of how closely the poll reflects the full population.

Selecting a random sample from a set is simple. But what about selecting a fair random sample from a set of unknown or indeterminate size? That’s where reservoir sampling comes in, and [Sam R… ...