Sample

A sample is a subset of a population. Since it is usually impractical to test every member of a population, a sample from the population is typically the best approach available.

Inferential statistics generally require that sampling be random although some types of sampling (such as those used in voter polling) seek to make the sample as representative of the population as possible by choosing the sample to resemble the population on the most important characteristics.

See also: biased sample and random sample