To learn more about the characteristics of a group of people, households, families, dwellings, and so on, one can either conduct a census or a sample survey.
- A census, usually carried out every 10 years, gathers data on all individuals, families, households and dwellings within a country. It involves counting every person and housing unit in a country and collecting data on key characteristics such as geographic, demographic, social and economic, among others. Additionally, it provides insights into households, dwellings and family characteristics.
- A sample survey is used to collect data for only a sub-part of the population of a country by examining a smaller selected group known as a sample in order to obtain information on the entire population of interest of a said country. It is crucial to ensure that the sample is representative of the population in question. Census data which provide detailed information, are often used to create an accurate and representative sample. The sample survey approach saves time and resources while still providing reliable information to estimate the characteristics of the whole population of interest. For example, to understand the average number of children per family, a sample survey will collect data from a representative group of families rather than collecting information from each family in the country.
A database containing information on a complete group of specific units is called a register. A register needs to be updated continuously to maintain its relevance. One example is a population register, which contains information about all residents in a country, includes names, addresses, birthdates, and other demographic data. Such a register (which will often be primarily used for administrative purposes) can then be used as the basis for a census or for the selection of a representative sample for a survey. Alternatively, a register may be used directly as a statistical data source instead of, or in addition to, a census or sample survey.
Another example can be a register containing information about all businesses in a country called a business register. It contains information on the name, address, employment, turnover, ownership etc. of the businesses in the country.
Watch the video proposed by the Croatian Bureau of statistics to learn about the Census of population, households and dwellings.