Page "Census" Paragraph 3

The census can be contrasted with sampling in which information is obtained only from a subset of a population, sometimes as an intercensal estimate.

Census data is commonly used for research, business marketing, and planning, as well as a baseline for sampling surveys.

Census counts are necessary to adjust samples to be representative of a population by weighting them as is common in opinion polling.

Similarly, stratification requires knowledge of the relative sizes of different population strata which are derived from census enumerations.

In some countries, census data are used to apportion electoral representation ( sometimes controversially – e. g., Utah v. Evans ).