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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; Ministry of Health and Long-Term Care; Peel Data Centre (PDC); Community Data Program (CDP), Canadian Council on Social Development (CCSD)
Cite as:
2001 Census, Statistics Canada
2006 Census, Statistics Canada
2011 Census, Statistics Canada
2016 Census, Statistics Canada


Data Collection Methods

  • Since 1951, the Census was administered by the Dominion Bureau of Statistics every five (5) years to Canadian residents. Starting in 1961, sampling was used to collect additional information, and computer facilities were used for the first time. By 1971, self-enumeration was introduced, and the Bureau was renamed Statistics Canada.
  • For the censuses administered between 1971 and 2006, two forms were used to collect information from residents, the “short form” and the “long form”. The short form collected information about basic population questions and nine housing questions. The long form collected the same information as the short form, with 20 housing questions and 30 additional socioeconomic questions. Between 1996 and 2006, 80% of households completed the short form census and 20% completed the long form census.
  • In 2011, the long form census was replaced by a voluntary National Household Survey (NHS). The content of the NHS varied slightly from the previous long form census and therefore comparisons had to be made with caution. See the National Household Survey page for more detailed information.
  • In 2016, the long form Census became mandatory once again, and was distributed to one out of every four households (25%). Income data were gathered solely by linking with administrative data (Canada Revenue Agency).

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.
  • Special custom geographies (e.g., Data Zones in Peel) and target groups (e.g., Recent Immigrants) have been obtained for the 2006 and 2016 Censuses, as well as the 2011 NHS.


  • Only data that are already aggregated are provided.
  • Prior to 1991, the Census did not enumerate non-permanent residents.
  • The Census undercounts some groups, such as the homeless and aboriginal people on reserves.
  • The Census can overcount other groups, such as young people counted as living at home while also counted while they are away at school.
  • These two types of errors result in net under-enumeration. Adjustments for this under-enumeration and for non-permanent residents have increased the Canadian population by 1.6% to 3.8%, depending on the census, province and age group.
  • Pooling of on-reserve aboriginal data into one division in the north makes interpretation difficult for areas with high aboriginal populations.
  • 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.


  1. Association of Public Health Epidemiologists in Ontario (APHEO).
    Census of Canada & National Household Survey. 2012.
  2. Statistics Canada. History of the Census of Canada. 2015.
  3. Statistics Canada. Timeline 100 years of the Canadian Census. 2018.
  4. Statistics Canada. Census of Population. 2017.

Last updated: February 12, 2019

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