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  • For each data source, information about data collection and analytical methods, limitations, the citation and additional resources can be found on the Data Sources and Methods page.


Original Source: Statistics Canada
Distributed by: Statistics Canada
Cite as:
2001 Census, Statistics Canada
2006 Census, Statistics Canada
2011 Census, Statistics Canada


Data Collection Methods

  • Since 1956, the Census is administered by Statistics Canada every five (5) years to all Canadian residents.
  • For the censuses administered in 1971, 1976, 1981, 1986, 1991 and 2006; two forms were used to collect information from residents. The short form and the long-form. The short form collects information about basic population questions and housing questions. The long-form collects the same information as the short-form, with more housing questions and additional socio-demographic questions. Between 1996 and 2006, 80% of households complete the short-form census and 20% complete the long-form census.
  • In 2011, the long-form census was replaced by a voluntary National Household Survey (NHS). The content of the NHS varies slightly from the previous long-form census and therefore comparisons should be made with caution. See the National Household Survey page for more detailed information.

Analysis Methods

  • Data are obtained in Beyond 20/20*.ivt format and are extracted by relevant geographies (province, census division (CD), census sub-division (CSD), census tract (CT), federal electoral district (FED), dissemination area (DA)) for Peel into Excel spreadsheets or into an Access database for further analysis.
  • Special custom geographies (e.g., Data Zones in Peel) and target groups (e.g., Recent Immigrants) have been obtained for the 2006 and 2011 Censuses.


  • Prior to 1991, the Census did not enumerate non-permanent residents.
  • The Census undercounts some groups, such as the homeless, young adults and aboriginal people on reserves.
  • In censuses, some people are not counted while others are counted more than once. These two types of errors result in net under-enumeration. Adjustments for this under-enumeration and for non-permanent residents has increased the Canadian population by 1.6% to 3.8%, depending on the census, province and age group.
  • Comparisons between censuses are affected by changes in question wording and in the definition of the population concerned.
  • Data from Statistics Canada are transformed using a random rounding process to maintain confidentiality. Values, including totals, are randomly rounded either up or down to a multiple of '5' or '10'. The result is that, when these data are summed or grouped, the total value may not match the sum of the individual values, since the total and subtotals are independently rounded. Similarly, percentages calculated on rounded data may not necessarily add up to 100%. Note also that the same value in the same table may be rounded up in one analysis and rounded down in the next.
  • Pooling of on-reserve aboriginal data into one division in the north makes interpretation difficult for areas with high aboriginal populations.


  1. Statistics Canada

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