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Modern censuses aim to enumerate every
person within a precisely delimited territory and sub area at a
particular moment in time (known as the census moment) using one of
two ap proaches
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A de jure census which
tallies people according to their regular or legal residence; |
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A de facto census which
allocates them to the place where they spent the night on the
day of enumeration. |
The definition of the census geography
and the census moment are crucial in the planning and conduct of a
census with the former requiring the use of extremely detailed maps
and the later providing the chronological line separating the
included from the excluded as well as the reference point for
questions such as age and marital status.
A fixed questionnaire is used for
interviewing and provides direct data such as name, address,
date of birth and occupation, some of which is used solely to guide
the enumeration process while most is used in the analysis stages.
The following is one list of desirable topics suggested by the
United Nations
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Geographic: Place
enumerated and/or place of usual residence; |
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Familial: Relation to head
of household or family; |
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Demographic: Sex, age,
marital status, children ever born, birthplace; |
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Economic: Type of
activity, occupation, industry, employer-employee status; |
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Social and Political:
Citizenship, language, ethnic or religious affiliation; and |
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Educational: literacy or
level of education, school attendance |
The direct data can in turn be used to
derive a entire set of new variables known as derived data.
This involves performing operations on one or more or the direct
data variables to create new values, classifications or indicators
such as total population, family composition and migration
data.
The depth and speed of analysis of
census data has evolved considerably with the introduction of
computers. In the 19th century tabulations were completed manually
thus restricting the amount and complexity of the analysis
performed. Today tabulations can be made relatively quickly and
products are made available in a wide range of formats and detail.
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