Dissemination Areas Explained

Similar to postal codes, all of Canada is divided into dissemination areas (DA). DA's are geographically larger than postal codes. Overall, there are approximately 54,000 DA's in Canada (versus 850,000 postal codes) and each DA consists of 400 to 700 individuals (approximately 250 households).

Dissemination areas are the smallest geographic areas used in the Canadian census. Because of this, DA's are often used by demographic firms and marketers as a basis for expanding upon census data. As for how DA's are defined, Statistics Canada divides the country into DA's by following a number of delineation criteria:

  1. Dissemination area (DA) boundaries respect the boundaries of census subdivisions and census tracts. DAs therefore remain stable over time, to the extent that census subdivisions and census tracts do.
  2. Dissemination area boundaries follow roads. DA boundaries may follow other features (such as railways, water features, power transmission lines), where these features form part of the boundaries of census subdivisions or census tracts.
  3. Dissemination areas are uniform in terms of population size, which is targeted from 400 to 700 persons to avoid data suppression. DAs with lower population counts (including zero population) may result in order to respect the boundaries of census subdivisions and census tracts. DA's with higher population counts may also result.
  4. Dissemination areas are delineated based on the block population counts from the previous census due to operational constraints.
  5. Dissemination areas are compact in shape, to the extent possible while respecting the above criteria.
  6. The number of dissemination blocks that are included in a dissemination area is limited to 99 due to operational constraints.

For more information on dissemination areas, please visit Statistics Canada.