Which data are included in Custom Areas

Please note: Custom areas are created using ABS 2016 boundaries.

For indicators within Community Insight Australia, data for custom areas are created in the following way:

  1. For custom areas where an entire SA1 is within the boundary of the custom area, the data value for this whole area is included.
  2. For custom areas where part of an SA1 is within the boundary of the custom area, it is included in the custom area if more than 50% of the SA1 is within the custom area.
  3. The data value for the SA1 depends upon what level the data is published to (eg SA1 or LGA level):
    • When data is available to SA1 level: We use the actual SA1 counts in these cases. For example, this is the case for ABS Census data.
    • When data is not available to SA1 level: As we do not know the exact data value for the SA1s, we apportion the published data to SA1 level. Population data from the census is available down to SA1 level and we use this data to get a weighting for each SA1. We calculate a percentage weighting using the population of the SA1 divided by the population of the LGA (or whatever area-types for which the data is published). We then apply this weighting to approximate the data value for the SA1s.
  4. Finally, the data for the custom area is created by summing up the data for the SA1s as per above.

If you have ideas on how this process could be improved, please let us know!