In science, to collect information from part of an entity, with the aim of learning about the entity as a whole (e.g., to collect information on a subset of the members of a population or on cores of ice from the Antarctic). The term sample size refers to the number of repeated measurements made (e.g., the number of individuals surveyed or the number of ice cores studied). All else being equal, the larger the sample size, the more confident we can be that our sample represents the entity as a whole and the more subtle the difference between samples that we’ll be able to discriminate.