• A census counts the population of a nation, state, or other geographic region. It records information about the population’s characteristics, such as age, sex, and occupation. It may also include data about the region’s agricultural and business sectors. National governments usually conduct censuses every five to 10 years, as recommended by the United Nations.

    Census data is commonly used for research, marketing, and planning. For example, population and housing data might determine where schools are constructed or where new bus routes are placed.

    In some countries, census data is used to figure out the number of representatives a given community will have in government. In the United States, for example, a county with a large population will have more representatives in state government than a less-populated one.

    Historical Censuses

    Many early civilizations used census data to determine how their governments would operate. Leaders of ancient Rome depended on censuses to govern their republic and, later, empire. Each male citizen had to appear before the census-takers and account for himself, his family, and his property. The Roman government determined the social position of each citizen by the amount of property he owned. Men with highly prized property enjoyed greater rights and freedoms.

    The most well-known historic census appears in the Domesday Book, a survey of England completed in 1086. Scholars say this survey determined the property rights of King William I (William the Conqueror). Assessors recorded how much property and assets—such as cattle and crops—citizens owned, and then taxed them accordingly. People and communities with valuable assets, such as fertile land or a source of water, were taxed more. William I had conquered England only 20 years earlier. The Domesday Book helped him evaluate what wealth his new kingdom held, and where strategic assets were located.

    The Incan Empire conducted perhaps the most unique census of the 15th century. The Incas, whose empire stretched across the Andes mountains, did not have a written language. They recorded information on quipus. A quipu is a rope made from llama or alpaca hair or cotton cords. A series of knots on the quipu defined certain numeric and non-numeric values. The Quipucamayocs, or quipu authorities, used these cords to keep track of mita, a form of taxes, and also to run a census of the local population. Quipus recorded the ages, occupations, and wealth of Incan citizens. Some remote Peruvian villages, although very few, still use the quipu system for official local government records.

    National Censuses

    Today, most national governments conduct censuses for planning purposes. New census-taking technologies and practices have helped governments achieve better results. For example, in 2006, Australia allowed citizens to complete parts of their census online in order to increase participation. In 2011, the country will implement the new Australian Statistical Geography Standard, which will allow census-takers to record more detailed data about populations in limited boundaries, such as postal areas.

    Nations organize their census information differently. Criteria are based on factors such as land size, government structure, and economic resources. With about 8.5 million square kilometers (3.3 million square miles) of territory to cover, Brazil records one of the most detailed collections of census data in the world. This collection includes ranked sets of data about the nation of Brazil, major regions, states, municipalities, districts, sub-districts, and neighborhoods.

    In 2010, Brazil implemented a number of strategies that aim to increase citizen participation in the census, especially in areas of the country that are hard to reach. Census-takers used handheld computers. These sophisticated computers record and store information on a country-wide broadband Internet service. This Internet service also permits citizens to answer some parts of the census questionnaire online. Finally, the handheld computers are able to translate the questionnaire into different indigenous languages, improving the participation of the many indigenous communities in Brazil.

    A country’s historical census data shows how the population has changed and gives clues about its history and politics. The Ugandan censuses in the first half of the 20th century are used to track the nation’s development. The censuses of 1911, 1921, and 1931 counted the population by “huts” and not individuals. “Huts” included both individuals and families.

    The 1948 and 1959 Ugandan censuses counted individuals, but divided the population between Africans and non-Africans. Uganda was a protectorate of the United Kingdom. The government had imported workers from other British territories in South Asia, mostly India. Often, ancestry was an indicator of social status. It was important to the government that the census distinguish between those of African, Asian, and European ancestry. After Uganda declared independence in 1962, censuses were taken jointly for all races.

    Preparing for and conducting a census requires a lot of time, resources, and work forces. The result is large sets of data that tell us about who and what make up our communities, regions, and countries. Ultimately, this data helps political leaders and citizens improve the places in which we live, work, and play.

    The first census of the U.S. population was conducted in 1790.

    Counting Up China
    How does the most populated country in the world count its population? China, with a population of about 1.3 billion, needed 6 million census-takers in 2010 to count every man, woman, and child in the country!

    Using the Force
    More than 400,000 people wrote "Jedi" as their religion on the 2001 census forms in Australia, Canada, England, New Zealand, Scotland, and Wales. More people considered themselves Jedi, an order of people from the Star Wars movies, than Jewish.

    Going Dutch
    The Netherlands has not conducted an official census since 1971 out of concern for individual privacy.

    Census of Marine Life
    In 2010, scientists finished the first-ever census of life in the world's oceans. The 10-year project, partly financed by the National Geographic Society, found there are nearly 250,000 known species in the sea. It also found more than 6,000 potentially new species.

  • Term Part of Speech Definition Encyclopedic Entry
    achieve Verb

    to accomplish or attain.

    alpaca Noun

    domesticated mammal related to the llama, native to South America.

    ancestry Noun

    family (genealogical) or historical background.

    ancient Rome Noun

    civilization founded on the Mediterranean Sea, lasting from the 8th century BCE to about 476 CE.

    Andes Mountains Noun

    mountain range extending along the western coast of South America.

    assessor Noun

    person who evaluates the worth of property or another valuable item, usually for taxation purposes.

    asset Noun

    property or another valuable item that is possessed by someone.

    broadband noun, adjective

    high-speed data transmission or communication where the bandwidth is shared by more than one signal.

    cattle Noun

    cows and oxen.

    census Noun

    program of a nation, state, or other region that counts the population and usually gives its characteristics, such as age and gender.

    Encyclopedic Entry: census
    characteristic Noun

    physical, cultural, or psychological feature of an organism, place, or object.

    citizen Noun

    member of a country, state, or town who shares responsibilities for the area and benefits from being a member.

    civilization Noun

    complex way of life that developed as humans began to develop urban settlements.

    Encyclopedic Entry: Key Components of Civilization
    conduct Verb

    to transmit, transport, or carry.

    county Noun

    political unit smaller than a state or province, but typically larger than a city, town, or other municipality.

    Encyclopedic Entry: county
    criteria Plural Noun

    set of standards or rules.

    crop Noun

    agricultural produce.

    Encyclopedic Entry: crop
    data Plural Noun

    (singular: datum) information collected during a scientific study.

    development Noun

    growth, or changing from one condition to another.

    Encyclopedic Entry: development
    distinguish Verb

    to differentiate or recognize as different.

    Domesday Book Noun

    (1086) census and survey of England, noting ownership of land and assets.

    economic Adjective

    having to do with money.

    empire Noun

    group of nations, territories or other groups of people controlled by a single, more powerful authority.

    evaluate Verb

    to decide something's worth.

    fertile Adjective

    able to produce crops or sustain agriculture.

    government Noun

    system or order of a nation, state, or other political unit.

    hut Noun

    simple, roofed structure usually made from natural materials such as wood and grasses.

    implement Verb

    to carry out plans.

    import Verb

    to bring in a good or service from another area for trade.

    Incan Empire Noun

    (1438-1533) empire stretching along the coastal highlands and Andes mountains of South America.

    independence Noun

    state or situation of being free.

    indicator Noun

    sign or signal.

    indigenous Adjective

    characteristic to or of a specific place.

    Encyclopedic Entry: indigenous
    Internet Noun

    vast, worldwide system of linked computers and computer networks.

    kingdom Noun

    type of government with a king or queen as its leader, or the land ruled by that king or queen.

    Encyclopedic Entry: kingdom
    llama Noun

    large mammal native to South America.

    marketing Noun

    art and science of selling a product.

    mita Noun

    form of required public service and tax in the Incan Empire.

    nation Noun

    political unit made of people who share a common territory.

    Encyclopedic Entry: nation
    neighborhood Noun

    an area within a larger city or town where people live and interact with one another.

    Encyclopedic Entry: neighborhood
    numeric Adjective

    having to do with numbers.

    occupation Noun

    job, work, or career.

    participation Noun

    taking part in an activity.

    permit Noun

    official, written permission to do something. Sometimes called a license.

    politics Noun

    art and science of public policy.

    population Noun

    total number of people or organisms in a particular area.

    property Noun

    goods or materials (including land) owned by someone.

    protectorate Noun

    territory controlled by another state or nation but not a part of it.

    questionnaire Noun

    short list of specific questions, whose replies can be used in research.

    quipu Noun

    knotted cord used by the ancient Incan Empire to record events, census data, and accounts. Also spelled khipu.

    quipucamayoc Noun

    census-takers and government workers in the Incan empire.

    region Noun

    any area on Earth with one or more common characteristics. Regions are the basic units of geography.

    Encyclopedic Entry: region
    remote Adjective

    distant or far away.

    representative Noun

    someone or something who acts in place of a group of people.

    republic Noun

    system of government where power rests in citizens who vote and representatives who stand for those citizens. The United States is a republic.

    research Noun

    scientific observations and investigation into a subject, usually following the scientific method: observation, hypothesis, prediction, experimentation, analysis, and conclusion.

    resource Noun

    available supply of materials, goods, or services. Resources can be natural or human.

    right Noun

    specific freedom or opportunity granted to an individual or organization based on the law.

    route Noun

    path or way.

    scholar Noun

    educated person.

    sector Noun

    section or a part of something.

    sex Noun

    male or female: division into which sexually reproducing organisms are divided.

    sophisticated Adjective

    knowledgeable or complex.

    state Noun

    political unit in a nation, such as the United States, Mexico, or Australia.

    strategic Adjective

    important part of a place or plan.

    survey Noun

    a study or analysis of characteristics of an area or a population.

    tax Noun

    money or goods citizens provide to government in return for public services such as military protection.

    technology Noun

    the science of using tools and complex machines to make human life easier or more profitable.

    unique Adjective

    one of a kind.

    United Kingdom Noun

    nation made of the countries of England, Wales, Scotland, and Northern Ireland.

    United Nations Noun

    international organization that works for peace, security and cooperation.

    William the Conqueror Noun

    (1027-1087) king of England. Also called William I.

    work force Noun

    number of people who are employed or available for employment.