DEFINITION OF INDIGENOUS
1 The term Indigenous is used in this publication to refer to Australian Aboriginal and Torres Strait Islander peoples. All ABS Indigenous population statistics are based on responses to the ABS standard question for Indigenous identification, which is used in self-enumerated collections. The same Census question has been used to determine Indigenous status (but not its component peoples) since the 1981 Census. The standard question format for Indigenous identification in the Census, that is shown below, was first used in this exact format in the 1996 Census, and was repeated in the 2001 and 2006 Census.
For more information on definitional changes and Census questions, refer to Occasional Paper: Population Issues, Indigenous Australians, 1996
(cat. no. 4708.0) or the Census Dictionary, 2006
(cat. no. 2901.0).
SCOPE AND COVERAGE
3 The 2006 Census of Population and Housing was held on 8 August 2006. Australia's first national Census was held in 1911 and since 1961 a Census has been taken every five years, the frequency specified in the Census and Statistics Act 1905. The objective of the Census is to count the number of people in Australia on Census night, identifying their key characteristics and those of the dwellings in which they live.
4 Following changes to the Australian Constitution as a result of the 1967 Referendum, Aboriginal and Torres Strait Islander peoples were included in official estimates of the Australian population. As a consequence, from the 1971 Census onwards, the ABS has developed and improved strategies to count the Indigenous population throughout Australia.
5 The Census aims to count every person who spent Census night in Australia. This includes Australian residents in Antarctica and people in the territories of Jervis Bay, Cocos (Keeling) Islands and Christmas Island. The other Australian External Territories (Norfolk Island and minor islands such as Heard and McDonald Islands), are outside the scope of the Australian Census. The only people who are in Australia on Census night, but who are excluded from the Census, are foreign diplomats and their families.
6 The Census includes people on vessels in or between Australian ports as well as people on board long distance trains, buses or aircraft. Also included are those people outside Australia who are not required to undertake migration formalities, such as those on oil and gas rigs or on Australian Antarctic bases. People entering Australia before midnight on Census night are counted while people leaving an Australian port for an overseas destination before midnight on Census night are not. Visitors to Australia are included regardless of how long they have been in the country or how long they plan to stay. However, for people who intend to be in Australia less than one year only basic demographic data are available. The Census includes homeless people and people camping out.
7 All occupied dwellings are counted in the Census with the exception of diplomatic dwellings. Unoccupied private dwellings are also counted, with the exception of unoccupied dwellings in caravan parks, marinas and manufactured home estates. Unoccupied residences of owners, managers or caretakers of such establishments are counted.
8 The 2006 Census data were collected by self-enumeration forms for the majority of people. Interviewer Household Forms (IHF) were used in discrete Indigenous communities where literacy and language problems made the self-enumeration procedure impractical. They were designed to be more culturally appropriate to Aboriginal and Torres Strait Islander peoples as well as easier for interviewers to use. They cover the same topics as the standard forms, with the exception of Community Development Employment Projects (CDEP) participation, which was only collected on the IHFs.
Indigenous Enumeration Strategy (IES)
9 The ABS invests considerable resources to ensure a high quality count of all people in Australia during the Census enumeration period. Counting the Indigenous population presents a number of challenges. To maximise the quality of the count, the IES has been designed as a supplementary strategy to regular Census collection procedures.
10 Since the 1976 Census, the ABS has used an evolving set of procedures tailored to the enumeration of Indigenous people. The 2006 IES built on this experience and had two main components:
- Alternative collection procedures to overcome potential barriers (e.g. language) to the effective counting of Aboriginal and Torres Strait Islander peoples.
- Census awareness activities aimed at encouraging Aboriginal and Torres Strait Islander peoples to both participate in the Census and be identified as Indigenous.
New approaches introduced in the 2006 IES to improve the Indigenous Census count include:
- Using Indigenous Engagement Managers, who have an ongoing role in the ABS's Indigenous Community Engagement Strategy, as Census State Indigenous Managers or assistants to State Indigenous Managers. The 2006 Census was the first Census conducted since the implementation of the ABS's Indigenous Community Engagement Strategy. More information on Indigenous Engagement Managers and the Indigenous Community Engagement Strategy is available on the ABS website <www.abs.gov.au> on the Indigenous theme pages.
- Developing more detailed strategies for the enumeration of Indigenous people in urban, regional and remote areas.
- Easing the administrative burden for interviewers in discrete communities by using a streamlined Interviewer Household Form in place of the separate Special Indigenous Household Form and Personal Form used in 2001.
Census in most discrete communities was conducted over a period of weeks around the Census date, known as a 'rolling enumeration'. This meant some communities were enumerated at different times. In the nominated discrete communities local people were recruited to act as supervisors and interviewers. Locally appointed staff helped in the enumeration of nominated discrete communities by liaising with the communities, assisting in planning workloads and, where necessary, assisting in the recruiting and training of interviewers. Urban Indigenous communities and the Indigenous peoples residing outside these communities were enumerated on standard Census Household Forms using self-enumeration procedures. In these areas, assistance was offered to households experiencing difficulties with self-enumeration.
13 Details about the 2006 Census content, collection operations, confidentiality and privacy protection, processing and evaluation activities are contained in 2006 Census of Population and Housing: Nature and Content (cat. no. 2008.0).
LIMITATIONS OF CENSUS DATA
14 Census data are subject to a number of inaccuracies resulting from mistakes by respondents or mistakes in collection or processing. Whilst many of these are corrected by careful processing procedures, some still remain. The effect of the remaining errors on the quality of the Census data is generally slight, although it may be more important for small groups in the population. The main kinds of quality issues to keep in mind are:
- Partial non-response: In some cases where an answer is not provided to a question an answer is imputed (often from other information on the form). In other cases a 'Not stated' code is allocated
- Processing error: While such errors can occur in any processing system, quality management is used continuously to improve the quality of processed data, and to identify and correct data of unacceptable quality
- Respondent error: Because processing procedures cannot detect or repair all errors made by people in completing the forms, some remain in final data
- Random adjustment: See paragraphs 42-46 of Explanatory Notes for more detail.
- Undercount: Although the Census aims to count each person, there are some people who are missed and others who are counted more than once. The data in this publication are not adjusted for the net undercount, with the exception of population estimates presented in Tables 1.1 - 1.4.
Further information on data quality is provided progressively in Census Update
and in 2006 Census Data Quality Working Papers
. These are available on the ABS website <www.abs.gov.au/census>.
DATA QUALITY INFORMATION
16 For the 2006 Census, data quality information is available on the ABS website. Data quality statements are available for each Census variable. They include the non-response rate for each Census variable and a brief outline of any known data quality problems.
OTHER ISSUES WITH INDIGENOUS DATA
17 For detailed information on population measures and data quality for Indigenous census data, see Population Distribution, Aboriginal and Torres Strait Islander Australians, 2006 (cat. no. 4705.0). Other issues with Indigenous data are also discussed in the Census Dictionary, 2006 (cat. no. 2901.0).
Population age structure
18 The Aboriginal and Torres Strait Islander population is a young population, with more people in younger age groups than older age groups. In 2006, half of the Indigenous population was aged 21 years or less. In contrast, in the non-Indigenous population, half the population was aged 37 years or less. These different age profiles of the Indigenous and non-Indigenous populations must be taken into account for some age related variables if the two populations are to be meaningfully compared.
19 In some chapters, such as Chapter 7:Work, the comparison of Indigenous and non-Indigenous populations is made between the 15-64 year age group to adjust for the larger proportion of older people in the non-Indigenous population with low participation rates. If the different age profiles are ignored, the comparison of labour force participation rates between Indigenous and non-Indigenous populations is distorted.
20 If data is to be compared at an aggregate level, rather than by age group, age standardisation can be used to take differences in population age structure into account. Age standardisation allows comparisons between two (or more) populations with different age structures, for a variable related to age. For more information on methods of age standardisation and age standardised comparisons refer to The Health and Welfare of Australia's Aboriginal and Torres Strait Islander Peoples (cat. no. 4704.0).
21 The calculation of household and personal income measures relies on information from the Survey of Income and Housing (SIH). SIH data in relation to the total population are used to estimate the median value for each of the income ranges against which individual income is reported in the Census. It is not known how appropriate these SIH total population medians are to those reported by the Indigenous population against these income ranges.
22 This publication uses a Canadian model for the concept of housing utilisation which is considered by the National Housing Strategy and the Australian Institute of Health and Welfare to conform reasonably to social norms in Australia. It is not known however to what extent the Canadian model can be considered to conform to norms for the Indigenous population of Australia. For more information, including a description of the derivation, see paragraphs 53-54.
23 Data in this publication are presented according to the Statistical Geography: Volume 1 Australian Standard Geographical Classification (ASGC), 2006 (cat. no. 1216.0). The geographical areas used are mainly from the main structure of the ASGC (Australia, and States and Territories), and areas from the Remoteness Structure. In this publication, the labels for Remoteness Areas categories have been abbreviated e.g. Major Cities of Australia is represented by Major Cities.
24 Within a State or Territory, each Remoteness Area represents an aggregation of non-contiguous geographical areas which share common characteristics of remoteness. While statistical data classified to this structure may be available by state or territory, characteristics of remoteness are determined in the context of Australia as a whole.
25 Therefore, not all Remoteness Areas are represented in each state/territory. The categories within the Remoteness Areas classification are:
- Major Cities of Australia. Comprised of Census collection districts with an average Accessibility/Remoteness Index of Australia (ARIA) value of 0 to 0.2.
- Inner Regional Australia. Comprised of Census Collection Districts with an average ARIA value greater than 0.2 and less than or equal to 2.4.
- Outer Regional Australia. Comprised of Census Collection Districts with an average ARIA value greater than 2.4 and less than or equal to 5.92.
- Remote Australia. Comprised of Census Collection Districts with an average ARIA value greater than 5.92 and less than or equal to 10.53.
- Very Remote Australia. Comprised of Census Collection Districts with an average ARIA value greater than 10.53.
- Migratory. Comprised of Off-Shore, Shipping and Migratory collection districts.
Data in this publication refer mostly to Census counts of all people within the scope of the Census, based on where they usually live (place of usual residence), rather than where they were on Census night (place of enumeration). Overseas visitors are excluded from place of usual residence data. The type of data used in each cell is clearly noted in the table or footnotes. The 2006 Census is the first Census to impute usual residence at CD level. Place of Usual Residence, as CD of usual residence, was allocated to all records where usual address was not stated or was left incomplete.
Basis for family and household data
27 Family variables are based on place of enumeration but are only derived for people counted at their usual residence. Temporarily absent persons are used to classify types of relationships and families existing in a household, but they are not used in the derivation of any other Census characteristics or in other Census output. If all members of a family are absent from their usual residence, no family records are created for them. Family and household structures are based on persons usually resident. If all members of a family or household are temporarily absent, the family or household is not counted. Overseas visitors and visitors from within Australia are also excluded from all such tables.
2006 Coding error with non-dependent children temporarily absent and dependent students (15-24) temporarily absent
28 A coding error has been identified with the fields CNDAF Count of non-dependent children temporarily absent and CDSAF count of dependent students (15-24) temporarily absent. Some temporarily absent persons (PTAs) have been excluded from these fields which will affect counts for number of children present in a family.
29 At Australia level, it affects 394 families for CNDAF and 572 families for CDSAF. This does not affect FMCF Family Composition, as the coding is correct in this field.
30 In this publication, households are divided into those with Indigenous residents, and other households. Both family and non-family households such as group households can be classified in this way.
31 An Indigenous household is any household that had at least one person of any age as a resident at the time of the Census who identified as having Aboriginal and/or Torres Strait Islander origins.
32 The following definitions are consistent with Census household definitions, and are used in this publication:
- Indigenous households. Includes households in occupied private dwellings with at least one person of any age as a resident at the time of the Census who identified as having Aboriginal and/or Torres Strait Islander origins. The other residents may have been identified as Indigenous, non-Indigenous, or have unknown Indigenous status.
- Other households. Includes households in occupied private dwellings not identified as Indigenous households as discussed above, because no residents were identified as Indigenous on Census night. These households include non-Indigenous residents or residents whose Indigenous status is unknown.
Households comprised wholly of visitors are excluded (wholly overseas visitors, wholly visitors from within Australia, or a combination of both), regardless of Indigenous status of individual residents.
34 Data relating to the characteristics of persons in these households (such as whether they are dependent children, earners, or certain ages), include persons temporarily absent on Census night and exclude visitors to the household. Up to three persons temporarily absent can be taken into account.
DATA PRESENTATION CONSIDERATIONS
35 There are two situations which result in Indigenous status being unknown: where Census forms are returned to the ABS with the Indigenous origin questions unanswered (question or item non-response); and where the ABS cannot obtain forms from persons identified in the field (imputed records). While most tables focus on a comparison of data for Indigenous and non-Indigenous persons, in this publication 'All persons' totals include persons whose Indigenous origin was unknown (not stated) and are footnoted to indicate this.
36 In this publication, counts for migratory and off-shore areas and Other Territories are included in totals for Australia. Other Territories includes Jervis Bay Territory, and the Indian Ocean Territories of Christmas Island and the Cocos (Keeling) Islands.
37 Components may not add within tables due to the inclusion of 'Other Territories', or persons with no usual address or enumerated in migratory CDs, in the Australia total.
Calculation of proportions
38 Unless otherwise stated, when calculating the proportion of the population with a particular characteristic, this publication does not include 'not stated ' responses in the denominator. For example, the proportion of people in Australia who work as Labourers would be calculated by dividing the number of people working as Labourers by the total population who indicated their occupation, and expressing the result as a percentage. The 'total population' only includes those who stated their occupation. Records coded to 'not stated' are listed underneath the total so other calculations can be made as necessary.
Calculation of medians
39 A median is the middle value in a series of numbers ordered by size. For example, in a series of seven numbers, the median value would be the fourth number in the series. In a series of eight numbers, the median value would be the average of the fourth and fifth number in the series. Unlike averages (means), which are calculated by summing all the values in a series and then dividing that aggregate by the number of observations in the series, medians are not usually skewed by extreme observations.
40 The categories 'not stated' and 'not applicable' are not included in the calculation of medians.
41 Median Income is the level of income which divides the units in a group into two equal parts, one half having incomes above the median and the other half having incomes below the median. Medians have been estimated for each income range using data from the Survey of Income and Housing.
42 On occasions, there are apparent discrepancies in tables between percentages and their sum total. This is caused by rounding.
Introduced random error
43 Under the Census and Statistics Act, 1905 it is an offence to release any information collected under the Act that is likely to enable identification of any particular individual or organisation. Introduced random error is used to ensure that no data are released which could risk the identification of individuals in the statistics.
44 Random adjustment of the data is considered to be the most satisfactory technique for avoiding the release of identifiable Census data. When the technique is applied, all cells are slightly adjusted to prevent any identifiable data being exposed. These adjustments result in small introduced random errors. However the information value of the table as a whole is not impaired. The technique allows very large tables, for which there is a strong client demand, to be produced even though they contain numbers of very small cells.
45 The totals and subtotals in summary tables are also subjected to small adjustments. These adjustments of totals and subtotals include modifications to preserve the additivity within tables. Although each table of this kind is internally consistent, comparisons between tables which contain similar data may show some minor discrepancies. In addition the tables at different geographic levels are adjusted independently, and tables at the higher geographic level may not be equal to the sum of the tables for the component geographic units.
46 It is not possible to determine which individual figures have been affected by random error adjustments, but the small variance which may be associated with derived totals can, for the most part, be ignored.
47 No reliance should be placed on small cells as they are impacted by random adjustment, respondent and processing errors.
48 New editions of the following classifications have been introduced since the 2001 Census and are available on the website:
- Australian and New Zealand Standard Classification of Occupations ANZSCO (cat. no. 1220.0). Responses to the occupation related questions, in the 2006 Census, are classified using the new Australian and New Zealand Standard Classification of Occupations (ANZSCO). Standard Census data is output based on this classification. However, 2006 Census occupation data will also be made available based on the Australian Standard Classification of Occupations (ASCO) Second Edition as used in the 2001 Census.
- Australian and New Zealand Standard Industrial Classification (ANZSIC) 2006 (cat. no. 1292.0). Responses to the industry of employment related questions, in the 2006 Census are classified using the new Australian and New Zealand Standard Industry Classification (ANZSIC) 2006. Standard 2006 Census data is output based on this classification.
- Australian Standard Classification of Cultural and Ethnic Groups (ASCCEG) Second Edition (cat. no.1249.0). Responses to the ancestry question, in the 2006 Census are classified using the new Australian Standard Classification of Cultural and Ethnic Groups (ASCCEG) Second Edition.
- Australian Standard Classification of Languages (ASCL), Second Edition (cat. no. 1267.0). The Australian Standard Classification of Languages (ASCL) Second Edition is used in the 2006 Census to code responses to the question 'Does the person speak a language other than English at home?'.
- Australian Standard Classification of Religious Groups (ASCRG), Second Edition (cat. no. 1266.0). The Australian Standard Classification of Religious Groups (ASCRG) Second Edition is used in the 2006 Census to code responses to the religion question. The first edition of ASCRG was used in the 2001 Census. The ASCRG was created to satisfy wide community interest in the religious affiliations of the Australian population and to meet a growing statistical and administrative need. Analysis of 2001 Census data highlighted the need for a minor review of ASCRG to ensure it would be as up to date as possible for use in the 2006 Census.
This classification replaces the Family Type classification used in the 2001 Census. Output is fully compatible with Family Type data: the key difference between the two classifications is that Family Composition reflects a more logical sequence of decision-making in family formation.
50 No provision has been made in the Family Composition classification for the identification of family members outside the family nucleus. Identification of such persons within a family is done by means of 'Relationship in household' data.
51 This classification replaces the Household Type classification used in the 2001 Census. Output for Household Composition is fully compatible with Household Type data. The structure of the Household Composition classification has been changed to allow integration with Family Composition as this better suits ABS output requirements and user needs.
52 The concept of housing utilisation in this publication is based upon a comparison of the number of bedrooms in a dwelling with a series of household demographics such as the number of usual residents, their relationship to one another, their age and sex. There is no single standard measure for housing utilisation. However, this publication has used a Canadian model which is considered by the National Housing Strategy and the Australian Institute of Health and Welfare to conform reasonably to social norms in Australia.
53 Housing utilisation measures in this publication have been calculated from person and household records for people living in occupied private dwellings, where there was sufficient information on household demographics and number of bedrooms.
The Canadian National Occupancy Standard
54 The Canadian National Occupancy Standard for housing appropriateness is sensitive to both household size and composition. The measure assesses the bedroom requirements of a household by specifying that:
- there should be no more than two persons per bedroom
- a household of one unattached individual may reasonably occupy a bed-sit (i.e. have no bedroom)
- couples should share a bedroom
- children less than five years of age of different sexes may reasonably share a bedroom
- children five years of age or older of the opposite sex should have separate bedrooms
- children less than 18 years of age and of the same sex may reasonably share a bedroom
- single household members 18 years or over should have a separate bedroom.
Households living in dwellings where this standard cannot be met are considered to be overcrowded.
56 Individual income is used as the basis for calculating household income. The Census collects gross (before tax) income in ranges, from people aged 15 years and over. The income ranges allow respondents to indicate a nil or negative income. Household income is calculated by summing the individual incomes reported by household members aged 15 years and over. Since the Census collects income in ranges, before individual income can be summed, a specific dollar amount needs to be allocated to each person. Median individual incomes for each range, derived using the ABS Survey of Income and Housing, are used for this purpose.
57 The level of economic well-being of a household is affected not only by the household's income, but also by its size and composition. For example, it would be expected that a household comprising two people would normally need more income than a lone person household if the two households are to enjoy the same standard of living. Equivalised household income is a measure used to take differences in household size and composition into account for comparison purposes. It is derived by calculating an equivalence factor according to the chosen equivalence scale, and then dividing income by the factor.
58 The equivalence factor used in this publication is the 'modified OECD' equivalence scale which is built up by allocating points to each person in a household. Taking the first adult in the household as having a weight of 1 point, each additional person who is 15 years or older is allocated 0.5 points, and each child under the age of 15 is allocated 0.3 points. Equivalised household income is derived by dividing total household income by a factor equal to the sum of the equivalence points allocated to the household members. The equivalised income of a lone person household is the same as its unequivalised income. The equivalised income of a household comprising more than one person lies between the total value and the per capita value of its unequivalised income.
59 When household income is adjusted according to an equivalence scale, the equivalised income can be viewed as an indicator of the economic resources available to a standardised household. For a lone person household it is equal to household income. For a household comprising more than one person, it is an indicator of the household income that a lone person household would need to receive to enjoy the same level of economic well-being. Alternatively, equivalised household income can be viewed as an indicator of the economic resources available to each individual in a household. This underpins the calculation of income distribution measures based on numbers of people, rather than numbers of households.
60 For further information on the calculation of equivalised gross household income, refer to Household Income and Income Distribution, 2005-06 (cat. no. 6523.0).
61 New topics for the 2006 Census included Need for assistance, Unpaid work and Dwelling Internet connection. A question on the number of children ever born was asked once again, in line with the 10 year cycle for this question.
Core Activity Need for Assistance (ASSNP)
62 This topic identifies people who report a need for assistance due to a 'profound or severe core activity limitation', and is based on similar criteria to the Survey of Disability, Ageing and Carers (SDAC). This population is defined as people who need assistance in their day to day lives with any or all of the following core activities - self-care, body movements or communication - because of a disability, long-term health condition, or old age.
63 It is relatable to SDAC and 2002 National Aboriginal and Torres Strait Islander Social Survey (NATSISS) concepts of profound/severe core activity limitation. The 2003 SDAC comprised a set of 75 questions about impairments, and functional limitations in relation to a range of tasks within each of the activity areas of self-care, mobility and communication. In comparison, the Census and NATSISS collections used much smaller sets of questions and provided fewer opportunities for people with profound/severe core activity limitation to be identified.
64 While this topic is based on the criteria used in SDAC, the population measured will differ as a result of the different collection methodology used and reduced question format. On this basis, data for this topic should be taken as an indication of the characteristics of people who report a need for assistance, not as the total prevalence of people with a 'profound or severe core activity limitation' as represented in the survey data.
65 This topic includes questions on providing child care, domestic work and voluntary work for an organisation or group, as well as assistance to people with a disability, long-term illness or problems related to old age. The questions are applicable to people aged 15 years and over.
66 Data is output using the variables:
- Unpaid child care
- Unpaid domestic work: number of hours
- Unpaid assistance to a person with a disability
- Voluntary work for an organisation or group
Number of children ever born (TISP)
The question on number of children ever born is asked in alternate censuses and was last asked in the 1996 Census.
Type of Internet connection (NEDD)
68 In the 2001 Census, there was a question asking each person about Internet and computer usage. This topic was reviewed for the 2006 Census, and the question relates now to the dwelling rather than to individuals.
69 Other ABS releases that may be of interest to users of this publication include:
- Australian Demographic Statistics (cat. no. 3101.0)
- Australia in Profile - A Regional Analysis (cat. no. 2032.0)
- Census Dictionary, 2006 (cat. no. 2901.0)
- Census of Population and Housing-Undercount, Australia, 2006 (cat. no. 2940.0)
- Community Profile Series: Indigenous Profiles (cat. no. 2002.0)
- Experimental Estimates and Projections of Indigenous Australians, 1991-2009 (cat.no. 3238.0)
- The Health and Welfare of Australia's Aboriginal and Torres Strait Islander Peoples 2005 (cat. no. 4704.0)
- How Australia Takes a Census (cat. no. 2903.0)
- Information paper: Measuring Net Undercount in the 2006 Population Census, Australia (cat. no. 2940.0.55.001)
- Population Distribution, Aboriginal and Torres Strait Islander Australians, Australia, 2006 (cat. no. 4705.0)
- Population Issues, Aboriginal and Torres Strait Islander Australians, 1996 (cat. no. 4708.0)
- Regional Population Growth, Australia: 1996-2006 (cat.no. 3218.0)
- Social Atlas Series (cat. no 2030.1-8)
- Statistical Geography: Volume 1 - Australian Standard Geographical Classification (ASGC), 2006 (cat. no. 1216.0)
- Statistical Geography: Volume 2 - Census Geographic Areas, Australia 2006 (cat. no. 2905.0)
- Statistical Geography: Volume 3 - Australian Standard Geographical Classification (ASGC) Urban Centres/Localities, 2006 (cat. no. 2909.0)