Also commonly referred to as sample. In statistics, a subsample is a subset of a population. Because it is often impractical to study an entire population, a subset of the population may be observed to instead. This subsample may then be used to estimate characteristics of the entire population. For example, if a scientist is studying the beak sizes of finches in the Galapagos Islands, she could collect data for some of the finches (a subsample) to make generalizations about the entire population (all of the finches on the island).