Census.
Publié le 10/05/2013
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Prior to any census, a census agency must develop an accurate list of addresses and maps to ensure that everyone is counted.
The U.S.
Census Bureau obtainsaddresses primarily from the United States Postal Service and from previous census address lists.
It also works closely with state, local, and tribal governments tocompile accurate lists.
Finally, census agencies often conduct an extensive marketing campaign before Census Day to remind the general population about theimportance of responding to the census.
This campaign may involve paid advertising, distributing materials by direct mail, promotional events, and encouraging mediacoverage of the census.
B Collecting the Information
Until relatively recently, population censuses were taken exclusively through personal interviews.
The government sent enumerators (interviewers) to each household in the country.
The enumerators asked the head of the household questions about each member of the household and entered the person’s responses on the censusquestionnaire.
The enumerator then returned the responses to the government.
Today, many censuses are conducted primarily through self-enumeration, which means that people complete their own census questionnaire.
Self-enumeration reduces the cost of a census to the government because fewer enumerators are needed toconduct interviews.
In addition, the procedure provides greater privacy to the public and generally improves the accuracy of responses, because household memberscan take more time to think over the questions and consult their personal records.
A country conducting a census chooses a collection technique based on its social and political traditions and technological capacities.
The United States census is highlyautomated and has been conducted primarily by mail since 1970.
For the 2000 U.S.
census, the Census Bureau offered many people the option of answering theirquestionnaires through the bureau’s Web site.
Canada began to use self-enumeration in 1971.
Today the Canadian government sends enumerators to deliver thecensus form to each household; the household head fills it out and sends it back to the government.
In both the United States and Canada, enumerators are sent tofollow up on households that do not mail back the census questionnaire.
Other nations continue to conduct censuses only through direct enumeration.
Some, such asTurkey, require people to stay home on Census Day to await the census taker.
Census agencies make a special effort to count people who may not receive a questionnaire by mail or who have no permanent address.
For example, the U.S.
CensusBureau sends census takers to interview people at homeless shelters, soup kitchens, mobile food vans, campgrounds, fairs, and carnivals.
It consults with experts tofind migrant and seasonal farmworkers.
The bureau works with the Department of Defense and U.S.
Coast Guard to identify people living on military installations orships.
The Census Bureau also counts military personnel and federal civilian government employees and their families who are living overseas.
Finally, the agencydistributes census questionnaires to people living in group quarters, such as college dormitories, nursing homes, hospitals, prisons and jails, halfway houses, youthhostels, convents and monasteries, and women’s shelters.
In the United States, Canada, and other countries, households receive either a short or long census questionnaire.
Most households receive the “short form,” a brief setof questions on basic characteristics such as name, age, sex, racial or ethnic background, marital status, and relationship to the household head.
But a small sample ofhouseholds receives the “long form,” which asks many other detailed questions.
These may include questions about the individual’s educational background, income,occupation, language knowledge, veteran status, and disability status as well as housing-related questions about the value of the individual’s home, the number ofrooms and bedrooms in it, and the year the structure was built.
The statistical technique of sampling —asking questions of only a representative sample of the population—allows census agencies to collect this detailed information without placing an undue burden on the population or creating an excessive cost to thegovernment.
About one in six households in the United States and one in five households in Canada receives the long form.
These sample sizes are large enough toproduce reliable information about the population characteristics of neighborhoods, regions, states or provinces, and the country as a whole.
C Processing and Analysis of Data
For most of the 19th century in the United States and Canada, census data were tabulated and compiled by hand, without the aid of machines.
Manual processing wasvery slow, and some figures were obsolete by the time they were published.
The invention of mechanical tabulating devices in the late 19th century made processing ofthe data much faster and improved the accuracy of the results.
Today, census questionnaires are processed primarily on computers and electronic equipment.
Besidesspeeding the processing of results, computers have made it possible to perform sophisticated analyses on the data and to draw correlations between various social andeconomic characteristics of the country.
For example, using census data, statisticians can easily determine the number of people living in Houston, Texas.
But they canalso determine the number of Houston women between the ages of 25 and 30 who have completed high school and are currently employed.
To process the data from hundreds of millions of paper questionnaires, the U.S.
Census Bureau employs an advanced system that scans every questionnaire into anelectronic image.
Then the images are analyzed by computer software that can recognize when a check-box item on the questionnaire has been marked with a pencil orpen.
Optical character recognition software analyzes handwritten responses on the questionnaire and translates them into electronic data.
Once in electronic form, thedata can be analyzed and turned into statistics.
Unreadable or ambiguous responses are checked by census clerks and manually keyed into the computer.
D Publication of Results
U.S.
and Canadian censuses publish only general statistical information and keep individual responses confidential.
By law, the U.S.
Census Bureau and Statistics Canadaare prohibited from releasing individual responses to any other government agency or to any individual or business.
Census workers in both countries must swear underoath that they will keep individual responses confidential.
Employees who violate this policy face a monetary fine and possible prison term.
If an individual’s personaldata were not kept confidential, people might refuse to participate in the census for fear that their personal information would be made public or used by thegovernment to track their activities.
In the United States, individual census responses are stored at the National Archives.
After 72 years, the original forms aredeclassified and opened to the public.
These original responses are frequently used by people researching the history of their families or constructing genealogies.
InCanada, census responses from 1906 and later are stored at Statistics Canada.
Microfilmed records of census responses from 1901 and earlier are stored at theNational Archives of Canada; these are the only individual census responses currently available for public use.
Until the 1980s, census agencies published their results in large volumes of numeric tables—sometimes numbering in the hundreds of volumes.
Today, the majority ofcensus data is distributed electronically, either through the Internet or on CD-ROM, diskette, or magnetic tape.
The Web sites of the U.S.
Census Bureau and StatisticsCanada provide online access to hundreds of statistical publications and data sets.
The U.S.
Census Bureau planned to disseminate results from the 2000 populationcensus primarily via its Internet site.
Both the U.S.
Census Bureau and Statistics Canada continue to distribute printed publications for the most commonly requesteddemographic information.
The Statistical Abstract of the United States, published annually by the Census Bureau, is an important statistical compendium on the social, political, and economic aspects of life in the United States.
This publication includes data from decennial censuses as well as from other sources, such as surveys takenbetween censuses.
Statistics Canada publishes a similar annual volume on Canadian statistics called the Canadian Year Book .
IV UNITED STATES CENSUSES
A census of U.S.
population has been conducted every ten years since 1790, as mandated by Article I, Section 2 of the Constitution of the United States.
The U.S.Census Bureau, established in 1902, conducts the census.
Before 1902 a separate office was set up for each census and then disbanded when the census was.
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