The Australian Bureau of Statistics (ABS) classification, Australian Statistical Geography Standard (ASGS), provides a common framework of statistical geography which enables the publication of statistics that are comparable and spatially integrated.
The ASGS structure has six hierarchical levels and each level directly aggregates to the level above.
For example, SA1s (Statistical Area Level 1) are aggregates of Mesh Blocks and aggregate to SA2s. This principle continues up through the remaining levels of the hierarchy.
Wherever possible, SA2s (Statistical Area Level 2) are based on officially gazetted State suburbs and localities. In urban areas SA2s largely conform to whole suburbs and combinations of whole suburbs, while in rural areas they define the functional zone of a regional centre.
SA2s should be allocated from whole addresses, utilising a geocoding service/tool. Statistical Services Branch (SSB) is gradually implementing this function for facilities in the Corporate Reference Data system (CRDS). SA2 is geocoded from whole addresses for public, private and previously declared hospitals, public residential aged care facilities, public community facilities and public young disabled residential care service facilities and SA2 for all the other facilities is allocated from suburb/locality and Australian postcode in the CRDS Locality data set. The CRDS Locality data set is a statewide standard that is primarily sourced from the ABS Locality to SA2 coding index and Australia Post postcode data.
The ABS Locality to SA2 coding index allocates localities to SA2s by searching for a locality/state/postcode combination to see which SA2 is associated with that locality. However, in cases where a locality/postcode/state combination covers more than one SA2 the boundary with the greater population is chosen as the associated SA2, which may not equate to the actual geographical location of the suburb/locality.
In the CRDS Facility Data Set, the SA2 represents the most populous from the current CRDS Locality data set, except for public, private and previously declared hospital facilities, public residential aged care facilities, public community facilities and public young disabled residential care service facilities where the SA2 represents the actual geographical location of the facility allocated by utilising Australian Bureau of Statistics (ABS) maps. For these facilities SSB has overridden the most populous SA2 with the SA2 representing the actual geographical location of the facility.
Examples where most populous SA2 overridden has not aligned with geographical location:
00117 Mungindi Hospital (1196 Moree Region to 1171 Balonne)
00172 Mackay Base Hospital (1346 Mackay to 1358 West Mackay)