City Stats

About the "Data selection wizard"

It is difficult to compare census data across locations and times; the census's demarcation of urban boundaries has changed over time, as have the labels used for ethnic "origins." For instance, consider the case of people originating in the British Isles. These are the categories available in each of the census years between 1961 and 2001:

If you want to track the segregation or integration of people originating in the British Isles over this forty-year period, it's necessary to agglomerate data for different sets of "origin" identities for each year. Similarly, tract divisions in each city change from census to census; in 1961, Victoria had 25 tracts, but by 2001, as a result of boundary changes, there were 68.

The objective of the wizard is to help you create queries which handle this variation in a simple manner, by specifying sets of origin labels for each year that can be treated as a single group, and by specifying a tract sets for each city, for each year. This should enable you to create more meaningful comparisons across years, cities and groups.

The wizard takes you through four steps:

  1. Choosing the years you're interested in. If you want to compare 1961 with 1971, you specify those two years.
  2. Specifying ethnicity groupings for each year. For instance, you could specify a grouping called "British Isles", for 1961, which includes all the five origin labels shown above (english, irish, other_british_isles, scottish and welsh), and treats them as a single entity.
  3. Selecting city/tract ranges for each year. If you're interested in Toronto and Vancouver, you can select specific tract ranges for each of those cities, for each year.
  4. Generating comparison tables. The wizard generates a complex query which it sends to the database, and retrieves three tables:
    • Table 1: Group Totals, Percentages, and Index of Dissimilarity (D).
    • Table 2: Interaction Index (xP*y: The exposure of group x to group y)
    • Table 3: Adjusted P* (xP*y / Proportion Y: Interaction Index expressed as odds ratio)
    These table types are explained here. Each table contains data for each of the "constructed ethnicities", for each of the city/tract sets specified, for each year.

These are some of the comparisons you can make using the wizard:

Try the wizard.