In a census survey , all units from the population of interest are analyzed. A related concept is the sample survey .

The main advantage of the census survey (as compared to the sample survey ) is that the whole population is involved and, therefore, there are no random errors or systematic errors caused by the sampling itself. The main shortcoming is the difficulty of practical realization if the population is large, e.g. the population of a whole country or a large city.

See also the short online course Survey Design and Sampling Procedures