Census of Population and Housing - Counts of Aboriginal and Torres Strait Islander Australians methodology

This publication presents results from the 1971 to 2021 Census of Population and Housing (Census).

For the respective methodologies, refer to the following:

• Historical Census data
• 2021 Census methodology

Indigenous status

In Australia, the method for collecting information about Indigenous status is through self-identification. The ABS Standard Indigenous question is used in all ABS data collections. It is also used across a wide range of government agencies and Australian Aboriginal and Torres Strait Islander organisations. For more information, see the Indigenous Status Standard, 2014, Version 1.5.

Responses to the Indigenous status question are captured automatically from mark box responses on the form, so the risk of processing error is minimised. Where respondents identify as both Aboriginal and Torres Strait Islander, they are instructed to mark both the 'Yes, Aboriginal' and 'Yes, Torres Strait Islander' boxes. In cases where a respondent marked both ‘No’ and ‘Yes’ boxes, their Indigenous Status is set to ‘Not stated’.

Indigenous status data is available from the 1971 Census onwards. A question on origin has been asked in every Census. However, prior to the 1971 Census, Aboriginal and Torres Strait Islander peoples were counted in order to exclude them from population estimates for each state and territory.

The 1971 and 1976 censuses asked each person's racial origin. Since the 1981 Census the word 'racial' has been dropped from the question. The 1996 Census was the first Census to allow people's origins to be recorded as both Aboriginal and Torres Strait Islander, prior to this only one or the other could be recorded.

No changes have been made for 2021.

For more information, see the the 2021 Census Dictionary entry for Indigenous status (INGP).

Indigenous status not stated

In every census, there are people who do not complete a census form but are in a dwelling that was considered occupied on Census night. In such cases, ABS imputes people into these dwellings. Imputation is the process that attempts to fill in basic information for the people who didn’t respond to the Census. Currently, this information is limited to a person’s age, sex, usual residence and marital status, but Indigenous status is not imputed. 

For more information on Indigenous status not stated in the 2021 Census, see section 3.5 of the Report on the quality of 2021 Census data: Statistical Independent Assurance Panel to the Australian Statistician.

Intercensal change

Intercensal change is the change between two Census periods. It is used to describe increases and decreases in Census counts over time. Intercensal change is calculated using counts and is expressed as a percentage.

There have been significant increases in the number of people identifying as having Aboriginal and/or Torres Strait Islander origin between Censuses that can impact intercensal change reporting.

Increases in the population are influenced by demographic factors such as births, deaths and migration, and by non-demographic factors including changes in whether or not a person identified as Aboriginal and/or Torres Strait Islander in each Census, the identification of children or others who have had their form completed by parents or someone else on their behalf, and the impact of communications and collection procedures. Changes in Indigenous status between Censuses can affect the interpretation of Census data for Aboriginal and Torres Strait Islander peoples. It is important to remember that Indigenous status is collected through self-identification and any change in how a person chooses to identify will affect the count of Aboriginal and Torres Strait Islander peoples in the Census. 

Sex ratio

Sex ratio is the number of males per 100 females.

Proportions

Proportions of persons by Indigenous status include 'not stated' responses in the denominator unless otherwise indicated. For example, the proportion of people in Australia who are of Aboriginal and/or Torres Strait Islander origin was calculated by dividing the number of persons identified as Aboriginal and/or Torres Strait Islander in origin by the total population and expressing the result as a percentage. The 'total population' includes records coded to 'not stated' unless otherwise indicated.

Torres Strait Region

Data for the Torres Strait Region in Tables 4.1 and 4.2 in ‘Queensland’ (see data downloads) includes:

• all Indigenous Locations (ILOCs) in the Torres Strait Indigenous Region (IREG)
• two ILOCs – Bamaga and surrounds and Seisia – from the Cape York IREG

These ILOCs were then filtered to only include the Statistical Area Level 1s (SA1s) that align with the Torres Strait Regional Authority, Regional Map.

The table below shows which SA1s and ILOCs were used to extract data for the Torres Strait Region.

The Australian Statistical Geography Standard (ASGS) provides a framework of statistical areas used by the Australian Bureau of Statistics (ABS) and other organisations to enable the publication of statistics that are comparable and spatially integrated. The ASGS provides users with a set of standard areas that can be used for analysing, visualising and integrating statistics produced by the ABS and other organisations. See the ASGS for further information.

The tables in this publication are presented by the following ASGS ABS Structures:

Main Structure

• State and Territory

Indigenous Structure

• Indigenous Regions (IREG), Indigenous Areas (IARE) and Indigenous Locations (ILOC)

Local Government Areas

• State and Territory

Greater Capital City Statistical Areas

• State and Territory

Remoteness Areas

• State and Territory

Further information about ABS statistical geography and a diagram of how the various ABS Structures interrelate can be found in the ASGS.

The Indigenous Structure is based on the Aboriginal and Torres Strait Islander peoples’ population distribution in the broader Australian community, so is ideal for analysis of Aboriginal and Torres Strait Islander data. In the ASGS Indigenous Structure, Indigenous Locations (ILOCs) are the smallest available unit. These are combined to create Indigenous Areas (IAREs) and then Indigenous Regions (IREGs). See the ASGS Indigenous Structure for further information.

The Remoteness structure is derived from the Accessibility/Remoteness Index of Australia Plus (ARIA+) produced by the Hugo Centre for Population and Migration Studies at the University of Adelaide. The base geography used to construct the five Remoteness Areas in the 2021 Census was different between 2011 and 2016; however, the impact of the change in classification is minimal. In most cases it is possible to make a comparison of the same Remoteness Area across two Censuses. For more information about the classification refer to Remoteness Structure | Australian Bureau of Statistics (abs.gov.au). For further information about the changes in Remoteness Areas between 2016 and 2021 refer to Remoteness Areas | Australian Bureau of Statistics (abs.gov.au).

This publication also includes tables for Empowered Communities Regions. The Empowered Communities Regions are unique to Empowered Communities and are not part of the ASGS. Further information about Empowered Communities is available on their website: Empowered Communities.