Census of Population and Housing: Estimating Homelessness methodology

165 Australian Bureau of Statistics (2016a) Census of Population and Housing: Understanding the Census and Census Data, Australia , 2016 (cat. no. 2900.0), Chapter: 'Item non-response rates'. Accessed 1 March 2018.

166 Australian Bureau of Statistics (2016) Census of Population and Housing: Details of Overcount and Undercount, Australia, 2016 (cat. no. 2940.0). Canberra: Australian Bureau of Statistics.

167 Australian Bureau of Statistics (2014) General Social Survey: Summary Results, Australia 2014 (cat. no. 4159.0). Canberra: Australian Bureau of Statistics.

168 Australian Bureau of Statistics (2009) Housing Mobility and Conditions, 2007–08 (cat. no. 4130.0.55.002). Canberra: Australian Bureau of Statistics.

169 Chamberlain, C and MacKenzie, D (2008) Australian Census Analytic Program: Counting the Homeless 2006 (cat. no. 2050.0) Canberra: Australian Bureau of Statistics.

170 Department of Immigration and Border Protection (2016), 2015–16 Humanitarian Programme Outcomes. Retrieved 5 September 2017.

171 Morphy, F (ed.) (2007) Agency, Contingency and Census Process: Observations of the 2006 Indigenous Enumeration Strategy in remote Aboriginal Australia Research Monograph, no. 28, Centre for Aboriginal Economic Policy Research (CAEPR) ANU, Canberra.

The Australian Bureau of Statistics (ABS) definition of homelessness is informed by an understanding of homelessness as 'home'lessness, not rooflessness. It emphasises the core elements of 'home' in Anglo American and European interpretations of the meaning of home as identified in research evidence (Mallett, 2004). These elements may include a sense of security, stability, privacy, safety and the ability to control living space. Homelessness is therefore a lack of one or more of the elements that represent 'home'.

In brief, the ABS statistical definition is that:

When a person does not have suitable accommodation alternatives they are considered homeless if their current living arrangement:

• is in a dwelling that is inadequate;
• has no tenure, or if their initial tenure is short and not extendable; or
• does not allow them to have control of, and access to space for social relations.
   

The definition has been constructed from a conceptual framework centred around the following elements:

• Adequacy of the dwelling;
• Security of tenure in the dwelling; and
• Control of, and access to space for social relations.
   

The elements are explained in more detail in the ABS Information Paper - A Statistical Definition of Homelessness (cat. no. 4922.0).

People must lack one or more of these elements to be defined as homeless. However, people who lack one or more of these elements are not necessarily classified as homeless. While homelessness is not a choice, some people may chose to live in situations that might parallel the living situations of people who are homeless. For example, people may be living in a shed while building a home on their own property, or on holiday travelling and staying with friends. These people have choice because they have the capacity to access other accommodation that is safe, adequate and provides for social relations. Having access to accommodation alternatives is contingent on having the financial, physical, psychological and personal means to access these alternatives (see the ABS Information Paper - A Statistical Definition of Homelessness (cat. no. 4922.0)).

The ABS definition of homelessness is used to produce statistics on homelessness from a range of ABS collections. This includes prevalence estimates of homelessness from the five-yearly Census of Population and Housing, and from household surveys such as the General Social Survey, Survey of Disability, Ageing and Carers, Personal Safety Survey, National Aboriginal and Torres Strait Islander Social Survey, and other surveys, as appropriate.

This definition can also be used by other organisations to collect and output their statistics in line with the ABS definition and ABS statistical outputs.

More information on the development of an ABS definition can be found in the 'Factsheet: Homelessness - in concept and in some measurement contexts', available from the 'Summary' tab of the Information Paper – A Statistical Definition of Homelessness, 2012 (cat. no. 4922.0).

The Information Paper - A Statistical Definition of Homelessness (cat. no. 4922.0) outlines which elements of the statistical definition are used in determining homeless living situations in each of the homeless operational groups.

The hierarchy below briefly outlines which elements of the definition are employed to determine the group as being homeless.

1. Includes a variety of tenure such as people staying in boarding houses, supported accommodation (long term and short term) and renters on month to month leases.
2. Note there will be lots of different situations some will lack control of space etc. but all will lack security of tenure

** An X for accommodation alternatives applies to any of the components of financial, personal, physical or psychological resources. If they do not exist the person's situation needs to be further considered in terms of the other elements on the table.
 

Mallett, S (2004) 'Understanding Home: A Critical Review of the Literature', The Sociological Review, 52 (1), 62-89.

This Appendix presents an overview of the consistent, transparent and repeatable Australian Bureau of Statistics (ABS) methodology for estimating the number of people enumerated in the Census of Population and Housing who may be homeless on Census night. More information on the methodology can be found in the publication: Information Paper - Methodology for Estimating Homelessness from the Census of Population and Housing (cat. no. 2049.0.55.001).

The following ABS methodology has been applied to producing homelessness estimates from the 2016, 2011, 2006 and 2001 Censuses of Population and Housing.

This methodology will also be applied to future Censuses. However, it may include improvements to both questions and field procedures as a result of 2021 Census developments, which will provide for new and better estimates for tracking future changes in homelessness. The transparency and repeatability of the methodology allows for an alternate estimate to be made that is consistent with 2016 to provide a link in monitoring change over time.

The methodology for use in the Census can only partially operationalise the definition because although the Census is designed for many purposes, it is limited in the nature of the questions it can ask that will reflect on homelessness. While the information derivable from the Census for homelessness measurement will improve over time, nevertheless some proxies will always need to be developed for some elements of the definition for some of the different homeless operational groups that can be output from the Census. Details on how each of the homeless groups relate to the definition can be found in 'Appendix 1: Definition of Homelessness', available from the 'Explanatory notes'.

The income, mortgage and rent cut-offs used in the rules for estimating homelessness are adjusted for each Census year. The cut-offs for 2016 Census are available in the 'Explanatory notes'.

Estimating the homeless operational group 'Persons living in improvised dwellings, tents or sleeping out' commences by first considering the group of Australian residents who were enumerated in the Census in an 'improvised home, tent, sleepers out' and who reported either being at home on Census night or having 'no usual address'.

The Census does not directly collect any data on the ABS homelessness definitional element 'adequacy of the dwelling'. This methodology does not assume that the 'Improvised home, tent, sleepers-out' category is a reasonable proxy, and both field and processing errors may overstate this group.

Nor does the Census currently directly collect information about accommodation alternatives, and proxy measures are needed to identify indicators of accommodation alternatives.

Neither the Census usual address question nor the dwelling category is designed to measure homelessness (Information about the purpose of the usual address question is available in the 'Explanatory notes'. Analysis of the reported characteristics of persons enumerated in dwellings classified by Census Field officers as 'improvised home, tents, sleepers-out', shows that many were unlikely to have been homeless.

There are a range of reasons why people may be in a dwelling classified as improvised, and which is reported as their usual address but who, however, are not likely to be homeless. In the 2006, 2011 and 2016 Censuses, Census Field officer notes showed that some dwellings classified as improvised dwellings were new homes being progressively occupied, or reflected large numbers of construction staff living in site sheds ('improvised dwellings') as they built new suburbs, highways or similar construction tasks. Some of the records classified as improvised dwellings appeared to relate to owner builders living in a shed or similar dwelling while building their home on their own property. The use of land, dwellings and property for these reasons is no different in 2016.

The ABS rules to classify homeless people who were enumerated in improvised dwellings on Census night are presented in the table below. The rules aim to avoid misclassification of the majority of the construction workers or owner builders who would have accommodation alternatives. Failure to do so would result in homelessness estimates being driven by building booms (when homelessness would appear to rise) and downturns (when it would appear to fall), and present an odd occupational grouping of the homeless.

To approximate the concept of accommodation alternatives applied to this group, variables such as tenure, income, rent and mortgage payments are used.

The following table presents the rules that are applied to classify persons who were most likely to be homeless on Census night and staying in improvised dwellings, tents and sleeping out. The rules start with the broad Census dwelling category of 'improvised home, tent, sleepers-out' and refines the category to avoid misclassifying as homeless those groups of people who were unlikely to be homeless on Census night.

As noted in the above table, imputed records have not been classified as representing homeless people. While no imputation is undertaken for rough sleepers, imputation is undertaken for an improvised dwelling which may have been occupied on Census night and about which the Census Field Officer was not 'absolutely certain was unoccupied' but for which no contact could be made. Detailed analysis was undertaken in 2006 supporting the treatment of imputed records for this homeless operational group. Further information can be found in the 'Feature Article 2: Methodology Used to Calculate Homeless Estimates', available from the 'Summary' tab of the publication Census of Population and Housing: Estimating Homelessness, 2006 (cat. no. 2049.0).

For more information on analysis of this group see the ABS publications: Discussion Paper: Methodological Review of Counting the Homeless, 2006 (cat. no. 2050.0.55.001) and the Position Paper - ABS Review of Counting the Homeless Methodology, August 2011 (cat. no. 2050.0.55.002).

The ABS considers that the vetting process to allocate people to the short supply of accommodation supplied under the Specialist Homeless Services (SHS) program and its predecessor the Supported Accommodation Assistance Program (SAAP) is unlikely to provide supported accommodation for those people who have accommodation alternatives, and that most supported accommodation does not provide the ABS definitional element 'security of tenure'.

To estimate the number of people in supported accommodation for the homeless on Census night in 2016, ABS first included all persons in dwellings identified by the Address Register or field officers as non-private dwellings and classified as 'hostels for the homeless, night shelter, refuge'. ABS then added people who were in dwellings flagged as being in supported accommodation using the Census 'list' strategy. In 2011 and 2006, there was an additional 'green sticker' strategy, whereby a physical sticker was census form in some sensitive supported dwellings. This was discontinued for 2016.

For the first time in 2016, the ABS asked people who were in crisis accommodation to write 'none-crisis' instead of just 'none' as their place of usual residence. This message was part of the homelessness enumeration strategy and was passed on through homelessness service providers. Persons who reported 'none-crisis' as their place of usual residence and were enumerated in a private dwelling that were estimated to be in supported accommodation.

Imputed persons are included in the estimates for this group because of the certainty of the nature of the dwellings flagged either by ABS staff, or by jurisdictions or services, and the irrelevance of the personal characteristics of occupants in ascertaining homelessness status for people staying in SHS properties.

Some supported accommodation, such as some transitional housing, may not meet the ABS definition of homelessness because the tenants have security of tenure in the dwelling. In general, information in the Census cannot distinguish the transitional housing properties that have security of tenure. While some extra information was collected to attempt to distinguish transitional housing management properties from other types of supported accommodation for the homeless, this was sometimes insufficient to accurately determine tenure.

The following table presents the rules that are applied to classify persons who were most likely to be homeless on Census night and staying in supported accommodation for the homeless. The rules start with the Census non-private dwelling category of 'hostels for the homeless, night shelter, refuge' and adds persons who were in a dwelling flagged as being supported accommodation through the 'list' strategy.

This group covers people for whom the elements of the ABS definition of homelessness that are lacking are 'security of tenure of the dwelling' and 'control, or access to social relations'. Visitors have no tenure. If they also, on balance, are most likely to lack accommodation alternatives then they are classified as homeless. Groups such as grey nomads, construction workers, recent migrants, other travellers are assumed, on balance, to have accommodation alternatives.

The homeless operational group 'Persons staying temporarily with other households' commences with the analysis of persons enumerated in any private dwelling structure (except an improvised home, tent, sleepers out) and who reported having 'No usual address'.

This group will contain people who were visiting on Census night for a range of reasons including those who are 'couch surfing'. It is unlikely that all of the people enumerated as 'visitors' without a usual address being reported on Census night meet the definition of homelessness.

People in private dwellings who report no usual address fall into two groups:

• visitors who report having no usual address and staying in a dwelling that also contains usual residents of that dwelling; and
• people staying in 'visitor only households' who report no usual address' and there are no usual residents in the dwelling.

Given the differences in the living circumstances on Census night of the two groups of people described above, each group needs to be considered using different judgements to determine whether the persons in the group are, on balance, likely to be homeless. Some of the people in 'visitor only households' will be families moving to a new location for work, people who have recently moved to, or returned to Australia and have not, or will not be living in their current property for six months or more in the Census year (given the Census takes place in August). In these circumstances they have correctly answered that they have no usual address, but they are not homeless.

Many other people in this visitor only household group were people travelling on Census night. Of these, the ABS classified one group as 'grey nomads' who were unlikely to be homeless and therefore were not included in the homeless population. Grey nomads are defined as people in dwellings where all people in the dwelling reported no usual address, were aged 55 years and over, were not in the labour force, and were staying in caravans on Census night.

Another group of people in 'visitor only households' were staying in properties (other than caravans) where the property was owned outright or on which they reported mortgage repayments. They were not staying with friends or relatives. These people were not included in the homeless estimates as the judgement was made that they reported no usual address because they were either travelling or moving primary residence, and staying in their holiday or second home at the time of the Census.

Another group of people in visitor only households were staying in properties (other than caravans) that they were renting. These people were not staying with friends or relatives and their characteristics suggested that they were travelling rather than being homeless on Census night.

The ABS also classified as not homeless people who were, on balance, most likely to be new migrants to Australia or returning to Australia to live. They were people who reported being overseas in August 2015, and who were renting or occupying premises on Census night and reported no usual address. For new migrants the year of arrival was 2016. On balance, most of the people within this group were unlikely to be homeless and had just not yet had the opportunity to settle in or back into Australia, or if they arrived in July or August would not be able to occupy their current address for six months in the year of the Census.

The ABS recognises that there are a number of groups that would be under represented in this homeless group of 'persons staying temporarily with other households'. These include youth, people fleeing domestic and / or family violence and Aboriginal and Torres Strait Islander Australians who may be homeless but for whom a usual address on Census night is reported. They cannot be separated from those people who were visitors on Census night (such as those on family holidays, visiting relatives etc.). This 'invisibility', for some, of the homeless condition in the Census dataset should be taken into consideration when using the data for this group.

ABS has not yet been able to implement any reliable way of estimating homelessness among youth staying with other households and for whom a usual address is reported in the Census. Service providers and researchers indicate that the low estimates of homeless youth staying with other households does not concord with their knowledge about youth homelessness. Guided by its Homelessness Statistics Reference Group, the ABS is continuing to undertake research and development to improve the estimation of homelessness, including youth homelessness.

Imputed records have not been classified as representing homeless people based on analysis of 2006 data. Further information can be found in the 'Feature Article 2: Methodology Used to Calculate Homeless Estimates', available from the 'Summary' tab of the publication Census of Population and Housing: Estimating Homelessness, 2006 (cat. no. 2049.0).

For more information on analysis of this group see the ABS publications: Discussion Paper: Methodological Review of Counting the Homeless, 2006 (cat. no. 2050.0.55.001) and the Position Paper - ABS Review of Counting the Homeless Methodology, August 2011 (cat. no. 2050.0.55.002).

The following table presents the rules that are applied to classify the persons who were most likely to be homeless on Census night and staying temporarily with other households. The rule starts with the broad Census dwelling category of persons enumerated in a private dwelling (which was not classified as an improvised home, tents, sleepers out) and who reported no usual address. The category is then refined for those groups of people who were unlikely to be homeless on Census night among two broad groupings:

• visitors who report having no usual address and staying in a dwelling that also contains usual residents of that dwelling; and
• people staying in 'visitor only households' who report 'no usual address' and there are no usual residents in the dwelling.
   

The element of the ABS definition of homelessness that people in boarding houses are assumed to lack is 'control of, and access to social relations', and their staying in boarding houses is assumed to reflect a lack of accommodation alternatives which together indicate homelessness. Note that halls of residence for students, dwellings for members of religious orders and institutions such as hospitals are not boarding houses for homeless people.

The homeless operational group 'Persons living in boarding houses' commences with analysis of persons enumerated in non-private dwellings that were classified by their owners / managers as 'boarding houses, private hotel'. It is expected that in most cases these boarding houses etc. have been correctly classified by the owner / manager. However, because the Census boarding house category is not designed to approximate homelessness, it will include some student halls of residence that are not part of any one school but serve multiple schools in a region. Rules are used to exclude from homelessness estimates those dwellings that, on balance, appear to be more likely to be a student hall of residence.

The rules also aim to reclassify other non-private dwellings as boarding houses where the characteristics of the people in the dwelling suggest that they may be housing large numbers of homeless people and can be assumed, on balance, to be more likely to be a boarding house although they were classified by the owner / manager as 'staff quarters', 'hotel, motel, bed and breakfast' or as a dwelling type that was not classifiable, or a classification was not stated.

The non-private dwelling type 'other or not classifiable' contains a variety of dwellings, including youth backpacker hostels and ski lodges. During validation it was identified that in some cases, these dwellings were being classified as likely to be homeless dwellings because they contained a large number of long term holiday makers, who were often not working, on low incomes, and reporting 'no place of usual residence'. In order to remove these from the homeless estimates, dwelling records in this category were scrutinised and removed if it was certain that they were holiday dwellings. This process was repeated for the 2011 estimates, and the population of this category has been revised downwards accordingly. For more information see the Explanatory notes.

The rules also attempt to reclassify any dwellings that were identified by the address register or Census field officers as private dwellings but the characteristics of the occupants are such that, on balance, they are more likely to be a boarding house rather than a large (apparently) unrelated group household. If a dwelling is a private dwelling, but operates illegally on the basis of multiple room by room tenancies, the address register or field officer may classify it according to its legal presentation rather than on the basis of its unobserved operation as a boarding house. The rules are applied to identify these dwelling amongst large (apparently) unrelated group households. However, this method is limited and is likely to overestimate the number of large (apparently) group households as boarding houses due to the limitations of the Census in capturing all relationships in the household. The Census only captures the relationships to the first person on the household form (and child relationships to person 2), so if people in the household are in couple relationships but neither of the couple is reported as person 1, then such households with five or more usual residents may be incorrectly classified as group households rather than the family household it really is. That same household may then also be incorrectly assumed to be a boarding house and its residents classified as homeless. The correct classification of households as family households can also be affected when there are persons who were temporarily absent (PTAs) on Census night.

Rules are applied to these large (apparently) unrelated group households to ensure that, on balance, households such as student households, retirement villages, nursing homes, homes for the disabled, convents / monasteries and other religious institutions are not incorrectly reclassified as boarding houses for the homeless.

For private dwellings additional steps ensure that dwellings are only counted as housing people living in boarding houses when the characteristics of the dwelling and the people residing in them corroborate with a boarding house situation.

From 2006, additional information available from the Census about need for assistance with core activities and volunteering is used to refine the rules to assist with ensuring the best possible reclassification of private dwellings as boarding houses. The aim of using these variables is to correctly classify dwellings that were more likely to be convents or monasteries (and other similar religious institutions) as well as for dwellings more likely to be facilities for the aged. The necessary items for this classification refinement were not collected in the 2001 Census. The rules for 2001 therefore omit these steps which refine the classification of boarding houses.

To determine, on balance, that the dwelling is most likely to have been a boarding house for homeless people, variables such as labour force status, student status, income, tenure type, need for assistance with core activities, religion and volunteering are used. These are shown in more detail in the table below. All of the variables such as income are applied to the individual in private dwellings rather than considering the household income, because if they are in boarding houses, individuals would not be sharing their economic resources.

There has been a minor review of the classification of religious groups for Census 2016. The code has been updated to reflect this and does not impact the statistics.

Additional steps applied in 2011 to include people in dwellings to be classified as boarding houses based on the list process have been repeated for 2016. The rules were further modified in 2016 to allow for cases where a boarding house was enumerated and classified as individual apartments due to having individual letter boxes, but additional information suggested that tenants only had a room rather than a self contained apartment, were sharing facilities such as bathrooms and kitchens, and the dwelling overall operated as a boarding house.

The following table presents the rules that are applied to classify persons who were most likely to be homeless on Census night and staying in boarding houses. The rules start with all persons enumerated in dwellings that were classified as 'boarding house, private hotel'. Then additional rules are applied to remove dwellings that are student halls of residences. Rules are applied to 'staff quarters' to pick up any that, on balance, were more likely to be boarding houses. Rules are also applied to 'hotel, motel, bed and breakfast' and 'other and not classifiable' or 'not stated' dwellings to identify if, on balance, they were more likely to be boarding houses. Finally rules are applied to private dwellings which appear to be large unrelated group households to determine if, on balance, they are more likely to be boarding houses.

The homeless operational group 'Persons in other temporary lodging includes people who reported having 'no usual address' on Census night who were enumerated in non-private dwellings which were classified by the Address Register or Census field officers as non-private dwellings and also classified by the building owner / manager as ‘hotel, motel, bed and breakfast’. People staying in other temporary lodgings who have no usual address lack the ABS homelessness definition element of 'security of tenure of the dwelling'. The rules then consider the income and employment status of these people to determine whether they could be considered to be homeless based on a lack of accommodation alternatives.

For the first time in 2016, the ABS asked people who were in crisis accommodation to write 'none - crisis' instead of just 'none' as their place of usual residence. This message was part of the homelessness enumeration strategy and was passed on through homelessness service providers. Persons who reported 'none - crisis' as their place of usual residence and were enumerated in a hotel, motel or bed and breakfast' were estimated to be in other temporary lodging.

The following table presents the rules that are applied to classify the persons who were most likely to be homeless on Census night and staying in other temporary lodgings. The rules start with the persons enumerated in the non-private dwelling category of 'hotel, motel, bed and breakfast' who reported no usual address and is refined to remove people who were, on balance, unlikely to be homeless on Census night.

People in severely crowded dwellings are considered to lack the 'control of, and access to social relations' element of the ABS definition of homelessness. Lack of accommodation alternatives is assumed for people living as usual residents in a severely crowded dwelling. The judgement is that people who had accommodation alternatives would not remain in such severely crowded circumstances.

The homeless operational group 'Persons living in 'severely' crowded dwellings' is operationalised as those usual residents of a private dwelling that, according to the Canadian National Occupancy Standard (CNOS), requires four or more extra bedrooms to accommodate the usual residents.

The concept of crowding 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 their sex.

There is no single standard or measure for housing utilisation, however the CNOS is widely used internationally and the ABS uses it for its measures of crowding for other purposes. It is a suitable standard for use with Census data because all of the required variables for its calculation are available from the Census, although family coding limits the suitability of it in large complex family households, and where persons may be temporarily absent on Census night.

The CNOS 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;
• children less than 5 years of age of different sexes may reasonably share a bedroom;
• children less than 18 years of age and of the same sex may reasonably share a bedroom;
• single household members 18 and over should have a separate bedroom, as should parents or couples; and
• a lone person household may reasonably occupy a bed sitter.
   

Households living in dwellings where this standard cannot be met are considered to be overcrowded.

There may be some underestimation associated with the application of the CNOS to Census data. It is not possible to create a CNOS estimate of the number of extra bedrooms needed for households where any key piece of information is missing. This includes the number of bedrooms or persons per dwelling, age of the persons, the relationship in household, in some cases, where at least one person (who is not the spouse of person 1) is temporarily absent on Census night. In addition, there may be cases where usual residents are not recorded on the Census form due to fear by the residents that they may be found to have more residents living in the dwelling than are allowed by their lease agreement. A final source of underestimation is if a person states that the dwelling is not their place of usual residence, they will be treated as a visitor and not included in the CNOS calculation, even if they actually are staying in the dwelling for an extended period.

Treating overcrowding as homelessness at this severe level of lacking four or more extra bedrooms is designed to prevent the misclassification of people as homeless who may choose to live together under some crowding to save money, to be close to family, or for other reasons. In addition, it also takes account of the limitation of the Census household form which only seeks relationship information within the household in relation to 'person 1', as well as child relationships to 'person 2'. This limitation of Census family coding results in misclassification of family relationships, particularly for large households with complex family relationships or households which contain multiple families, or where persons are temporarily absent. Households that look like crowded group households in the Census may actually include a number of couples. Under the CNOS a single adult requires their own bedroom but a couple can share a bedroom, and the masking of relationships can inflate the crowding measure.

The boundary of four or more extra bedrooms required in the Census data aligns with the concept of extreme or severe crowding, and aligns reasonably well with results from ABS surveys, and avoids overestimation from Census data at lower thresholds due to family coding, persons temporarily absent and potential errors in the numbers of bedrooms being reported.

Other Census variables are not applied to imply accommodation alternatives in severely crowded dwellings. While some of the residents may own the dwelling in which they live in severely crowded conditions, the presence of other people that contribute to crowding demonstrates loss of the power to exercise control and choice in this living situation.

For the first time in 2016. the housing utilisation variable HOSD is available in standard Census outputs, although numbers will vary from the homelessness estimates publication for persons who have already previously been classified in other homelessness groups. In addition, in a small number of Northern Territory Aboriginal and Torres Strait Islander communities, supplementary information was available to determine number of bedrooms where this was 'not stated' in the Census data. This has been included and those dwellings allocated a CNOS value where possible.

The following table presents the rules that are applied to classify the persons who were, on balance, most likely to be homeless on Census night and live in severely crowded dwellings. The rule starts with the persons enumerated in private dwellings where the dwelling would require four or more extra bedrooms under the CNOS and then refines the group by removing people who have already been considered as homeless in the other homeless groups.

The ABS presents, alongside the homeless estimates from the Census, estimates of the number of people in selected marginal housing circumstances. These are limited to categories that can be obtained from the Census. Other marginal housing, such as housing with major structural problems or where residents are in constant threat of violence, cannot be obtained from the Census and are therefore not included.

These marginal housing groups not only provide an indication of the numbers of people living in marginal housing close to the boundary of homelessness, but can also provide a possible indication of people who may be at risk of homelessness.

Three marginal housing groups are classified from the Census:

• persons living in other crowded dwellings - those who were not living in 'severely' crowded dwellings;
• persons in other improvised dwellings - those who were living in improvised dwellings but were not considered homeless under the rules for the group 'Persons living in improvised dwellings, tents or sleeping out'; and
• persons who are marginally housed in caravan parks.
   

Each of these groups is discussed below.

Persons living in other crowded dwellings are those usual residents living in dwellings reported in the Census where the dwelling requires three extra bedrooms to accommodate them according to the CNOS (for more details see the section above 'Persons living in 'severely' crowded dwellings'). Under the operationalisation of the ABS definition they are not classified as homeless but are considered to be in marginal housing and may be at risk of homelessness.

The following table outlines the rules used to estimate the number of persons living in other crowded dwellings and ensures that no person who has already been counted as homeless is also counted in this marginal housing category.

Persons in other improvised dwellings are those people who were enumerated on Census night in the dwelling category of an 'improvised home, tent, sleepers-out' who reported either being 'at home' on Census night or having no usual address, and are not considered, on balance, to be homeless (see above on 'Persons living in improvised dwellings, tents or sleeping out'). Under the ABS definition they are not classified as homeless because they have accommodation alternatives, in many living situations, the dwelling will be adequate. They are, however, included in marginal housing and may be at risk of homelessness.

The following table outlines the rules used to estimate the number of persons living in other improvised dwellings and ensures that no person who has already been counted as homeless or in other crowded dwellings is also counted in this marginal housing category.

Persons marginally housed in caravan parks are those considered to be in marginal housing and at risk of homelessness. Prior to the 2016 Census, Caravan data were grouped together with cabin and houseboat. For the 2016 Census this is available separately through an individual category, however for the purposes of this operational group the ABS has included both 'Caravan' and 'Cabin or Houseboat' categories. In both cases they must be located in a caravan park. Some people they have chosen to reside in a caravan park due to work, or due to convenience, cost or location and could select other accommodation alternatives, and rules are incorporated to exclude these people.

The following table outlines the rules used to estimate the number of persons marginally housed in caravan parks and ensures that no person has already been counted as homeless or in other crowded dwellings is also counted in this marginal housing category.

The Census of Population and Housing aims to count everyone in Australia on Census night. This requires a method of enumeration that is efficient and effective, while ensuring the information collected is of the highest quality. A "digital first" approach was adopted for 2016 Census, where key changes included the use of the Address Register and the move towards a predominantly mail-out census enumeration model. The 2011 Census conversely relied extensively on a large workforce in the field who provided updates on the characteristic of a dwelling, and delivered and collected forms.

As in previous Censuses, in 2016 there were a range of approaches used for collecting information from specific population groups. These approaches were designed in consultation and collaboration with relevant communities and/or service providers to ensure the coverage of all people in Australia (including these specific populations) was as complete as possible. The enumeration strategies relevant to the homelessness estimation are the Homelessness Enumeration Strategy and the Aboriginal and Torres Strait Islander Strategy.

In the 2011 Census, households who preferred not to return a paper form were given the option to report online, in which about 34% of private dwellings responded in this manner. For more information about the method for collecting 2011 Census data, please refer to How Australia Takes a Census, 2011 (cat. no. 2903.0).

For 2016 the Australian Bureau of Statistics (ABS) adopted a 'digital first' approach anticipating an increased preference for online reporting. In fact, about 59% of private dwellings responded online. This new method addressed the difficulties in recruiting Census field staff as well as investing in the advantages and efficiencies of new technologies. The three main changes from that used in earlier Censuses were:

• the development of a national Address Register to support mailing out of materials to households across Australia. The Address Register was formed using the Geocoded National Address File (GNAF) as its base and then built on using information gained through visiting every address through a large canvassing exercise, in addition to analysing other available data. This register formed the basis of addresses to which information was mailed out;
• the postal delivery of an instruction letter detailing how to complete the Census online or how to request a paper form. Paper forms were then despatched and mailed back via Australia Post so that Census Field Officers only visited a minority of homes, where the use of the mail service was not considered viable or where a Census form had not been returned; and
• the use of a smarter online form. Many enhancements were made to the online form to improve quality and make it easier for respondents to complete.
   

This method has sometimes been referred to as a ‘mail-out’ model, and it significantly reduced the number of Census Field Officers and the hours of Census Field Officer effort required to undertake Census enumeration. Approximately 80% of dwellings across Australia were, in the first instance, mailed a Census instruction letter which included a unique login number for the online form. Some adaptations to the standard mail-out model were deployed to encourage timely response from people in areas where the standard approach may not have been as effective.

In the remaining areas of Australia, a more traditional delivery approach (the 'drop off' approach) was used with Census Field Officers delivering materials to each dwelling, enabling householders to either complete their form online or mail back a paper form. In these areas, the Census Field Officers attempted to make contact with householders when dropping off the form, only making further visits to dwellings that have not participated.

The collection methodology is described in more detail in Census of Population and Housing: Nature and Content, Australia, 2016. (cat. no. 2008.0).

The Homelessness Enumeration Strategy was designed to complement the mainstream Census and other special strategies to maximise the overall enumeration of the homeless population. It targets the enumeration of 'rough sleepers', 'couch surfers' and persons in supported accommodation for the homeless.

The approach for counting 'rough sleepers' was to focus on 'hot spots', using information received from service providers. ABS then worked closely with service and accommodation providers in awareness raising and local engagement in those areas, and recruited specialist field staff to help count people sleeping rough.

As in previous censuses, a collection period of one week spanning Census night was used to cover the various 'hot spot' locations. The use of Special Census Collectors, and particularly staff recruited from homelessness services, was designed to not only use their expertise to locate people sleeping rough, but also to ensure that the information collected relates only to those people sleeping rough on Census night (with no likelihood that they were enumerated elsewhere) and that they are not enumerated more than once in the 'hot spot' locations. The absence of mainstream Census collectors in the mail-out areas close to Census night diminished the ability of the ABS to identify the presence of homeless individuals/groups in unexpected areas, so increased engagement with service providers was essential to mitigate this change.

The Special Short Form was again generally used to enumerate 'rough sleepers'. However, to account for the different context of people sleeping rough in Northern Australia (including the Northern Territory and northern parts of Western Australia and Queensland) the mainstream household form was also used which captures more comprehensive information for groups of people sleeping rough.

The identification of 'couch surfers' on mainstream forms was again given greater emphasis where the ABS ran targeted promotion campaign, through homelessness agencies, to encourage people who were experiencing homelessness to write 'None' in response to the usual address question on the Census form to indicate clearly that they had no usual address.

A new initiative was introduce for the 2016 Census, where persons being brokered to stay temporarily at a hotel, motel, or other accommodation were asked to write 'None - crisis' in response to the usual address question. Brokerage is typically arranged when accommodation is full at a homelessness service. The aim of this initiative is to further distinguish occupants staying in these other temporary lodgings who are there due to the person experiencing homelessness.

As in previous Censuses, the ABS again used a 'list' strategy to support ABS classification of dwellings that were supported accommodation for the homeless. ABS obtained lists of addresses of supported accommodation from government bodies, individual Specialist Homelessness Services (SHS) providers and umbrella homelessness services organisations. In 2016 ABS also sought information about whether the type of supported accommodation was short-term, long-term or mixed.

The Green Sticker Strategy used in 2011 was discontinued in 2016. The Green Sticker Strategy was used to enumerate homeless persons in supported accommodation where respondents were instructed to attach a Green Sticker to their completed Census form, to enable this return to be associated with the homeless strategy. The change of method in 2016 meant there was an increased reliance on the collection of supported accommodation lists to enable the correct classification of sensitive supported accommodation establishments and their occupants

New lists of boarding houses (both registered and illegal boarding house operations) were sought from jurisdictions and homelessness service providers in 2016 and were received from New South Wales, Victoria, Queensland, South Australia, and Northern Territory. Western Australia does not have a state-based register yet information is available at the local council level. Tasmania has no requirement to maintain a register while legal boarding houses do not operate in the Australian Capital Territory.

Since 1976, measures have been adopted to maximise coverage of the Aboriginal and Torres Strait Islander population. These include specific Census awareness activities, greater use of Aboriginal and Torres Strait Islander staff, greater involvement of Aboriginal and Torres Strait Islander organisations, and better coordination of the related field operations.

The 2016 Census campaign’s Aboriginal and Torres Strait Islander strategy targeted people living in urban and regional areas, as well as those living in town camps and discrete communities. It used multiple channels of communication, specific messaging, mainstream and Aboriginal and Torres Strait Islander media, and culturally-specific design, music and talent to reach this audience group. Engagement with community groups, intermediaries, Aboriginal and Torres Strait Islander leaders, elders and Census supporters was also an important part of the communication strategy.

The 2016 Discrete Communities and Remote Areas Strategy incorporated improvements to enumeration of Aboriginal and Torres Strait Islander people living in remote Aboriginal and Torres Strait Islander communities. At a broad level, the improvements for the 2016 Census included:

• earlier and ongoing engagement;
• a reduction in the overall enumeration period for Aboriginal and Torres Strait Islander communities;
• an increase in the number of field staff recruited; and
• a greater level of support to Aboriginal and Torres Strait Islander people requiring assistance in completing their form (in both urban and remote areas).
   

In nominated discrete communities the procedures included interviewing each Aboriginal and Torres Strait Islander household using a tailored Interviewer Household Form (IHF) - and employing local people, where possible, to conduct the interview.

For the 2016 Census the ABS also incorporated improvements to assist Aboriginal and Torres Strait Islanders living in urban communities to participate in the Census. As part of this strategy in pre-identified urban areas increased support and assistance was provided to Aboriginal and Torres Strait Islander people, including the option of collecting Census information through an interview.

For the first time, people in Norfolk Island on Census Night were included in the Australian Census, following passage of the Norfolk Island Legislation Amendment Act 2015.

The practice of collecting Aboriginal and/or Torres Strait Islander status via observation was discontinued in the 2016 Census. For enumeration via observation, a response to this question was recorded only if the Aboriginal and/or Torres Strait Islander status of the person was confirmed by a service provider to whom the person is known, otherwise the question was left blank and coded to ‘Not Stated’ in the Census dataset.

Targeting of overcrowded dwellings was dropped for 2016 due to being deemed ineffective in past Censuses. Ensuring a full response within a dwelling proved challenging, as it relied on the awareness and compliance of all residents. Some households may have intentionally omitted residents from the household form for fear or repercussions from landlords or housing authorities. Further to this, the paper household form could only accommodate six present persons (and households needed to request a second paper form to report more people), while the online Census can accommodate a maximum of ten.

People who identified themselves as being of Aboriginal origin, Torres Strait Islander origin, or both.

The address register was developed as the central source of addresses used in collection information to support 2016 Census, as well as all household and business collections. The main input to the Address Register is the Geocoded National Address File (G-NAF), supplemented by other available address data sources and field work by Australian Bureau of Statistics (ABS) Field Officers.

Refers to a person’s age. The 2016 Census form asks respondents to provide the date of birth for each person on the form, or age in years if date of birth is not known. Age is calculated from date of birth when provided, otherwise stated age is used.

Australia is defined in the Standard Australian Classification of Countries (SACC), 2016 (cat. no. 1269.0) and includes the states and territories and the other territories of Christmas Island, Cocos (Keeling) Islands, Jervis Bay Territory and Norfolk Island. It excludes the other Australian external territories (Australian Antarctic Territory, Heard and McDonald Islands, Ashmore and Cartier Islands and the Coral Sea Territory). In 2011 and previous Censuses, Norfolk Island was not included in the definition of geographic Australia. Christmas and Cocos Keeling Islands have been included since the 1996 Census.

Australian born includes all people born in Australia and excludes people:

• born at sea,
• whose response was classified 'Inadequately described, or
• whose response was classified 'Not elsewhere classified'.
   

Refers to people who state they have Australian Citizenship. 

The Australian Institute of Health and Welfare (AIHW) is a major national agency set up by the Australian Government under the Australian Institute of Health and Welfare Act to provide reliable, regular and relevant information and statistics on Australia's health and welfare. This agency manages and produces the Specialist Homelessness Services (SHS) Collection.

The Australian Statistical Geography Standard (ASGS) is the geographical standard used by the ABS since July 2011 for the collection and dissemination of geographic statistics. It is a hierarchically structured classification conceptually based on Mesh Blocks and is split into two broad groups, ABS structures and the Non-ABS structures to satisfy different statistical purposes. The ASGS ABS Structures used in this publication are:

• Statistical Area Level 2 (SA2)
• Statistical Area Level 3 (SA3)
• Statistical Area Level 4 (SA4)
• State/Territory (STE)
• Australia (AUS)
• Greater Capital City Statistical Areas (GCCSA) and
• Remoteness Area (RA).
   

The ASGS Non-ABS Structure used in this publication is:

• Local Government Area (LGA).
   

For more information refer to the ABS geography page https://www.abs.gov.au/geography and the publication Australian Statistical Geography Standard (ASGS): Volume 1 - Main Structure and Greater Capital City Statistical Areas (cat. no. 1270.0.55.001).

See Mean.

See Country of birth.

The Canadian National Occupancy Standard (CNOS) for housing appropriateness is sensitive to both household size and composition. CNOS assesses the bedroom requirements of a household by specifying that:

• there should be no more than two persons per bedroom;
• children less than 5 years of age of different sexes may reasonably share a bedroom;
• children 5 years of age or older of 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, as should parents or couples; and
• a lone person household may reasonably occupy a bed sitter.

Households living in dwellings where this standard cannot be met are considered to be overcrowded. 

Enumeration of people in caravans varies depending on their situation. Occupied caravans are usually treated as private dwellings with the exception of some caravans on residential allotments.

• Caravans on Residential Allotments: An occupied caravan on a residential allotment is usually treated as an occupied private dwelling. The exception to this is where there are one or more other structures on the allotment and the occupants of the caravan are residents of the main dwelling. In this case the occupants are all classed as one household and the caravan is counted as an additional room of the main dwelling.
• Caravans on Roadsides/Open Land: Since the 2006 Census, caravans on roadsides/open land are treated the same as caravans in caravan parks. They are treated as occupied private dwellings and the occupants of the caravans complete Household forms. Prior to the 2006 Census, occupied caravans at roadside parking areas or on open land were classified as 'sleepers-out' for the variable Dwelling Structure.

See also Dwelling Structure.

The Australian Census of Population and Housing is an official count of population and dwellings, and collects details of age, sex, and other characteristics of that population. For more information see the Census page 
https://abs.gov.au/census, How Australia Takes a Census, 2011 (cat. no. 2903.0) and the publication Census of Population and Housing: Nature and Content, Australia (cat. no. 2008.0).

ABS obtained lists of addresses of supported accommodation and boarding houses from government bodies, individual Specialist Homelessness Services (SHS) providers and umbrella homelessness services organisations. 

In 2016 ABS also sought information about what type of supported accommodation was provided i.e. whether it was crisis or transitional housing etc. Some of the lists ABS received included this extra detail, some did not. 

Lists of boarding houses (both registered and illegal boarding house operations) were sought from jurisdictions and homelessness service providers in 2016 and were received from New South Wales, Victoria, Queensland, South Australia, and Northern Territory. Western Australia does not have a state-based register yet information is available at the local council level. Tasmania has no requirement to maintain a register, while legal boarding houses do not operate in Australian Capital Territory. 

The Census counts people where they were located on Census night and this count of the population is referred to as the place of enumeration count. A count of the population based on their place of usual residence is also available. While every effort is made to achieve a complete Census count, some underenumeration inevitably occurs for various reasons, for example, the inadvertent omission of very young children, treatment of some dwellings as unoccupied when in fact they are occupied, and failure to find all dwellings. Refusal by householders to complete the Census form is not a significant cause of underenumeration.

This is a person of any age who is a natural, adopted, step, foster or nominal son or daughter of a couple or lone parent, usually resident in the same household. A child is also any individual under 15, usually resident in the household, who forms a parent-child relationship with another member of the household. This includes otherwise related children less than 15 years of age and unrelated children less than 15 years of age. In order to be classified as a child, the person can have no identified partner or child of his/her own usually resident in the household. A separate family in the household is formed in this instance. If a person is aged under 15 and has a partner and/or a spouse these relationships are not recorded.

This is a person who has been classified as a child of another household member and who is aged under 15 years. A person who is classified as a child aged under 15 is considered to be a dependent child.

The Core Activity Need for Assistance variable has been developed to measure the number of people with a profound or severe disability. The variable was first included in the 2006 Census. For the Census, people with a profound or severe disability are defined as those people needing help or assistance in one or more of the three core activity areas of self-care, mobility and communication, because of a disability, long-term health condition (lasting six months or more) or old age.

The basic counting unit for homelessness estimation is the person. This counting unit provides for the richness of their personal characteristics (including relationships with others) for analysis as well as analysis by their living situation.

The Census records a person's country of birth. The Standard Australian Classification of Countries (SACC) (cat. no. 1269.0) is used to classify responses for Country of Birth. This classification uses the current names of countries, so if a person uses a former name, the current name is coded. For example, Siam would be coded to Thailand.

A couple family is identified by the existence of a couple relationship. A couple relationship is defined as two people usually residing in the same household who share a social, economic and emotional bond usually associated with marriage and who consider their relationship to be a marriage or marriage-like union. This relationship is identified by the presence of a registered marriage or de facto marriage. A couple family can be with or without children, and may or may not include other related individuals.

Each stage of the Census is subject to stringent quality assurance procedures which result in data of high quality. However, in a Census there are recognised sources of error and some of these may survive in the data produced. Potential sources of error in the Census are: underenumeration, respondent error, processing error and introduced random error. Introduced random error is used to protect the confidentiality of individuals. The effect of such errors on overall Census results is generally insignificant and does not impair the usefulness of Census data.

Yet, as homelessness estimates are estimated from Census using analytical techniques, using both the characteristics observed in the Census and assumptions about the way people may have responded to particular Census questions, there are limitations of the Census data where underestimation or overestimation may occur for some homeless groups.

See also Overestimation and Underestimation.

The ABS has implemented procedures tailored to the enumeration of Aboriginal and Torres Strait Islander people living in discrete communities and remote areas since the 1976 Census. These targeted procedures are in place to improve coverage, accuracy and quality of the data. At a broad level, these procedures include:

• earlier, detailed and ongoing engagement;
• flexibility of the field operations and staff to ensure that for each area the appropriate enumeration methodology is used and documented;
• procedures which enhance the collection of data and to allow for closer management of the field operation and the tracking of progress; and
• a greater level of support to Aboriginal and Torres Strait Islander people who need assistance.

Prior to enumeration, Local Engagement Managers are employed in select areas, with an aim of undertaking local engagement and intelligence gathering, to work with the Regional Management Unit to lay the groundwork for a successful enumeration by working with local organisations to raise awareness, and to build networks that can assist in identifying applicants for the new positions. In Aboriginal and Torres Strait Islander communities and some remote areas, a tailored interview form is used. In these cases the staff employed to undertake the enumeration train and work with people from the community so that the people from the community can conduct the interviews. In other pre-defined areas, with high Indigenous populations, Census staff provide a greater level of support in completing Census forms by offering to conduct an interview if necessary.

See also Interviewer Household form

Violence by any member of the person's household (e.g. partners, parents, siblings, children, housemates, and other household members).

A dwelling is a structure which is intended to have people live in it, and which is habitable on Census night. Some examples of dwellings are houses, motels, flats, caravans, prisons, tents, humpies and houseboats. Private dwellings are enumerated using online or paper household forms, which obtain family and relationship data as well as information on the dwelling itself such as rent or mortgage payments and ownership.

Non-private dwellings (hotels, hospitals etc.) are enumerated on personal forms. 

All occupied dwellings are counted in the Census. Unoccupied private dwellings are also counted. This includes unoccupied units in retirement villages (self-contained). Unoccupied residences of owners, managers or caretakers of caravan parks, marinas and manufactured home estates are also counted, but other unoccupied dwellings in such establishments are not counted. Non-private dwellings with zero occupancy on Census Night are not included in the homelessness estimates.

Dwelling Location applies to private dwellings, and describes the location of dwellings other than 'typical' private dwellings. The majority of private dwellings will appear in the 'Other' category.

There has been a change in the way this information is collected. In 2016, it was recorded by ABS Address Canvassing Officers in the lead up to the Census as part of establishing the Address Register as a mail-out frame for designated areas. In areas enumerated using the traditional approach of delivering forms, the information was collected by ABS Field Officers during the Census collection period. Location of private dwelling data was also updated as required by ABS Field Officers during the 2016 Census enumeration period. 

This variable classifies the structure of private dwellings enumerated in the Census.

There has been a change in the way this information is collected. In 2016, it was recorded by ABS Address Canvassing Officers in the lead up to the Census as part of establishing the Address Register as a mail-out frame for designated areas. In areas enumerated using the traditional approach of delivering forms, the information was collected by ABS Field Officers during the Census collection period. Location of private dwelling data was also updated as required by ABS Field Officers during the 2016 Census enumeration period.

Prior to the 2016 Census, Caravans data were grouped together with cabin and houseboat. For the 2016 Census this will be available separately through an individual caravan category. Cabin and houseboat data remain together.

The broad categories are: 

Separate house: This is a house which is separated from other dwellings by a space of at least half a metre. A separate house may have a flat attached to it, such as a granny flat or converted garage (the flat is categorised under Flat or apartment - see below). The number of storeys of separate houses is not recorded. Also included in this category are occupied accommodation units in manufactured home estates which are identified as separate houses. 

Semi-detached, row or terrace house, townhouse, etc.: These dwellings have their own private grounds and no other dwelling above or below them. They are either attached in some structural way to one or more dwellings or are separated from neighbouring dwellings by less than half a metre. 

Flat or apartment: This category includes all dwellings in blocks of flats or apartments. These dwellings do not have their own private grounds and usually share a common entrance foyer or stairwell. This category also includes flats attached to houses such as granny flats, and houses converted into two or more flats.

Caravan: This category includes all occupied caravans, regardless of where they are located. Occupied campervans are also included. For further detailed information see Caravans in this glossary. 

Cabins and Houseboats: This category includes all occupied cabins and houseboats. Cabins are self-contained and not intended for long term residential use. This includes occupied cabins located in residential parks or set up as temporary accommodation. A Houseboat is an occupied mobile dwelling (intended for use on water). It is not typically intended for long term use (although it could be currently used on a permanent or semi-permanent basis). Occupied houseboats are treated as occupied private dwellings regardless of location. It also includes occupied small boats.

Improvised home, tent, sleepers-out: This category includes sheds, tents, humpies and other improvised dwellings, occupied on Census night. This category also includes people sleeping out, such as those sleeping on the streets, in abandoned buildings, under bridges or in cars. 

House or flat attached to a shop, office, etc.: A house or flat attached to a shop, office, factory or any other non-residential structure is included in this category. 

See also Caravans, Dwelling, Dwelling Location, Dwelling Type, Tenure Type, Type of Non-Private Dwelling.

There has been a change in the way this information is collected. In 2016, it was recorded by ABS Address Canvassing Officers in the lead up to the Census as part of establishing the Address Register as a mail-out frame for designated areas. In areas enumerated using the traditional approach of delivering forms, the information was collected by ABS Field Officers during the Census collection period. Dwelling type was also updated as required by ABS Field Officers during the 2016 Census enumeration period.

Dwelling Type classifies all dwellings into the basic dwelling types. The categories are:

Occupied Private Dwelling: An occupied private dwelling is a private dwelling occupied by one or more people. A private dwelling is most often a house or flat. It can also be a caravan, houseboat, tent, or a house attached to an office, or rooms above a shop. Occupied dwellings in caravan/residential parks or camping grounds are treated as occupied private dwellings. Dwellings located in caravan/residential parks or camping grounds can be identified by using the variable Dwelling Location. 

Unoccupied Private Dwellings: These are structures built specifically for living purposes which are habitable, but unoccupied on Census night. Vacant houses, holiday homes, huts and cabins (other than seasonal workers' quarters) are counted as unoccupied private dwellings. Also included are newly completed dwellings not yet occupied, dwellings which are vacant because they are due for demolition or repair, and dwellings to let. Unoccupied private dwellings in caravan/residential parks, marinas and manufactured home estates are not counted in the Census. The exception to this is residences of owners, managers or caretakers of the establishment and, from the 2006 Census, unoccupied residences in retirement villages (self-contained). 

Non-Private Dwellings (NPD): NPDs are those dwellings, not included above, that provide a communal or transitory type of accommodation. They are classified according to their function for the variable Type of Non-Private Dwelling. NPDs include hotels, motels, guest houses, prisons, religious and charitable institutions, boarding schools, defence establishments, hospitals and other communal dwellings. People in NPDs are enumerated on personal forms and so information on their family structure is not available. In the case of accommodation for the retired or aged, where the one establishment contains both self-contained units and units that are not self-contained, then both household forms (self-contained) and personal forms (not self-contained) are used as appropriate. Unoccupied NPDs are not enumerated in the Census, with the exception of residences of owners, managers or caretakers within an NPD. 

Migratory: People enumerated on an overnight journey by plane, train or bus cannot be allocated a dwelling type. This category exists for processing purposes only. 

Off-Shore: This includes dwellings such as off-shore oil rigs, drilling platforms and the like. Prior to the 2006 Census, it also included people enumerated aboard ships in Australian waters.

Shipping: This dwelling type is for people enumerated aboard ships in Australian waters. For the 2001 and earlier Censuses, they were included in the 'Offshore' category.

See also Dwelling Location, Dwelling Structure, and Type of Non-Private Dwelling.

See Level of Highest Educational Attainment.

Every Census since 1911 has included a question in which respondents reported their highest level of educational achievement. In the 1966 Census, respondents were asked to provide details of the qualification title and the institution at which it was obtained. In all Censuses since 1966, people aged 15 years and over have been asked whether they had obtained a qualification and, if so, the qualification name and field of study. The 1971 Census also asked whether the person was currently studying for a qualification and, if so, its name. Prior to 2001, this information was restricted to post-school educational qualifications. From 2001, the information includes all qualifications (both school and post-school) and the level and field of the highest qualification.

See Labour Force Status.

See Place of enumeration, Place of Usual Residence.

The Estimated Resident Population (ERP) is the official measure of the Australian population, and is based on the concept of usual residence. It refers to all people, regardless of nationality or citizenship, who usually live in Australia, with the exception of foreign diplomatic personnel and their families. The ERP includes usual residents who are overseas for less than 12 months and excludes overseas visitors who are in Australia for less then 12 months.

A family is defined by the ABS as two or more persons, one of whom is at least 15 years of age, who are related by blood, marriage (registered or de facto), adoption, step or fostering, and who are usually resident in the same household.

Each separately identified couple relationship, lone parent-child relationship or other blood relationship forms the basis of a family. Some households contain more than one family.

Non-related persons living in the same household are not counted as family members (unless under 15 years of age).

Visiting families are not included as part of the household, and the relationships of other visitors are not coded. A household containing only a visiting family (e.g. a family at a holiday home) is coded to a household type of visitors only. 

Where all persons present are aged under 15 years, or where information for each person has been imputed, the household is deemed not classifiable to a family. Of people listed as temporarily absent, only spouse(s) and family children are used in coding family composition.

Violence against a person by any family member (e.g. sibling, resident and non-resident family members).

The Census records the full/part-time status of students.

The General Social Survey aims to collect data for persons aged 15 years and over on a range of social dimensions from the same individual to enable analysis of the interrelationships in social circumstances and outcomes, including the exploration of multiple advantage and disadvantage experienced in Australia.

Grey nomads are defined as people in dwellings where all people in the dwelling were aged 55 years and over, were not in the labour force, and were staying in caravans, cabins or houseboats on Census night, and reported having no usual address. The majority of these grey nomads were enumerated in holiday destinations.

The ABS defines a group household as a household consisting of two or more unrelated people where all persons are aged 15 years and over. There are no reported couple relationships, parent-child relationships or other blood relationships in these households.

An unrelated child (e.g. boarder) under the age of 15 who lives in a household with one or more usual residents, is coded as forming a parent-child relationship within that household. These households become family households, not group households.

The Census records the highest level of primary or secondary school a person has completed. Highest year of school completed is classified to the Australian Standard Classification of Education (ASCED).

This classification has changed since the 2001 Census. In 2001 it included a category 'Still at school'. The 'Still at school' category is excluded from the 2011 and 2006 classification. This allows the level of highest educational attainment to be determined for people still at school.

Everyone in Australia at Census time needs to be counted in the Census, excluding foreign diplomats and their families, no matter where they may be sleeping on Census night. To achieve this, the ABS has developed a strategy to obtain the best possible enumeration of people, no matter where they sleep. Some aspects of this strategy include liaising with service providers and engaging specialised field staff to count people sleeping rough on a special interview based form, and providing the ability for people to respond to the usual residence question as 'none' if they have no usual residence.

The ABS definition of homelessness is informed by an understanding of homelessness as 'home'lessness, not rooflessness. Homelessness is therefore a lack of one or more of the elements that represent 'home'. In accordance with this definition, when a person does not have suitable accommodation alternatives they are considered homeless if their current living arrangement:

• is in a dwelling that is inadequate; or
• has no tenure, or if their initial tenure is short and not extendable; or
• does not allow them to have control of, and access to space for social relations.
   

See for more information the Information Paper - A Statistical Definition of Homelessness (cat. no. 4922.0).

ABS has developed six homeless operational groups for presenting estimates of people enumerated in the Census who were likely to have been homeless on Census night.

These groups are:

• Persons living in improvised dwellings, tents, or sleeping out;
• Persons in supported accommodation for the homeless;
• Persons staying temporarily with other households;
• Persons living in boarding houses;
• Persons in other temporary lodgings; and
• Persons living in 'severely' crowded dwellings.
   

See the 'Explanatory notes' section of this publication for information on other marginal housing groups.

Advisory group to the ABS on the development, collection, compilation, production and dissemination of robust statistics for the use in analysing, understanding and reporting on homelessness in Australia. 

The Census records the number of hours worked in all jobs held during the week before Census night, by employed people aged 15 years and over. This excludes any time off but includes any overtime or extra time worked. Hours worked, when used in combination with Labour Force Status, provides information on full-time and part-time employment. For Census purposes, a person is considered to be working full-time if they worked 35 hours or more in all jobs during the week prior to Census night.

Occupied houseboats have been classified as occupied private dwellings since the 1986 Census, and therefore receive household forms. Unoccupied houseboats are not counted. 

A household is defined as one or more persons, at least one of whom is at least 15 years of age, usually resident in the same private dwelling. Under this definition, all occupants of a dwelling form a household and complete one form. Therefore, for Census purposes, the total number of households is equal to the total number of occupied private dwellings as a Census form is completed for each household from which dwelling information for the household is obtained. 

The Census records the type of household within a dwelling. Household Composition indicates whether a family is present or not and whether or not other unrelated household members are present.

A maximum of three families can be coded to a household. Lone person households can contain visitors. Visitor only households can contain overseas visitors.

The household form is the primary means for collecting Census data and is used in all private dwellings. A personal form records person characteristics in cases where a household form is not appropriate. If there are more than six people in a household on Census night, a personal form is completed for the seventh person and any subsequent persons.

Household is the sum of the individual incomes of each resident present in the household on Census night. If any resident aged 15 years and over is temporarily absent, or does not state their income, then a value for Total Household Income is not derived for that household. These households will be categorised as: 'Partial income stated' or 'All incomes not stated'.

• 'Partial income stated' is used when some household members (aged 15 years and over) are temporarily absent or have not stated their income.
• 'All incomes not stated' is used when no member of the household (aged 15 years and over) has stated their income.
   

In most cases, the income of visitors to a household is excluded. The exception to this is households that comprise only visitors. Household income is calculated for these households in order to collect data on household income in tourist areas.

The 2011 and 2006 Censuses collected individual income in ranges, so before these could be summed to a household level a specific dollar amount needed to be imputed for each person. Median incomes for each range, derived using data from the 2003–04 and 2007–08 Survey of Income and Housing, were used for the purpose of compiling household income measures. For more information see the Information Paper: Survey of Income and Housing, User Guide, Australia, 2007–08 (cat. no. 6553.0) and the Household Expenditure Survey and Survey of Income and Housing: User Guide, 2003–04 (cat. no. 6503.0)

This method, which imputes personal income values within reported individual income ranges, was selected as the best practical approximation that would result in the majority of households being included in the same Census household income range that would have been derived had individuals reported their incomes in dollar amounts rather than in ranges. The approximations are expected to generally support analyses looking at various other characteristics of both persons and households in terms of broad household income ranges.

The imputation used in deriving household income is likely to understate some household incomes, specifically lower household incomes in general but particularly for single income households. Single income households with lower income levels are most affected by the imputation methodology understating their incomes.

A more general issue with individual income reporting in the Census is that studies have shown individuals tend to understate their incomes compared with the amounts that would be reported in surveys designed specifically to measure income.

For the above reasons, care should be exercised in any use of Census household income information, which relies on the imputed values. Similar care should be taken when using 2001 Census data.

See Explanatory notes for more information.

See Household Composition.

See Canadian National Occupancy Standard (CNOS).

See Dwelling; Dwelling Structure.

Imputation is a statistical process for predicting values where no response was provided to a question and a response could not be derived. 

Where no Census form is returned, the number of males and females in 'non-contact' private dwellings may be imputed. In addition, the following key demographic variables may also be imputed if they are 'Not stated':

• Age
• Place of Usual Residence
• Registered Marital Status
• Sex
   

The imputation method used since the 2006 Census is known as 'hotdecking'. In general this method involves locating a donor record and copying the relevant responses to the record requiring imputation. The donor record will have similar characteristics and must also have the required variable(s) stated. In addition the donor record will be located geographically as close as possible to the location of the record to be imputed. The match must occur within the same Capital City or Balance of State

The methodology for imputation is tailored depending on whether no Census form or a partially completed form was returned.

See Explanatory notes for more information

Each Census respondent aged 15 years and over is asked to indicate the range within which their gross income from all sources lies (rather than their exact income).

Total income, also referred to as gross income, is the sum of income received from all sources before any deductions such as income tax, the Medicare Levy or salary sacrificed amounts are taken out. It includes wages, salaries, overtime, business or farm income (less operating expenses), rents received, dividends, interest, superannuation, maintenance (child support), workers' compensation, and government pensions and allowances (including all payments for family assistance, labour market assistance, youth and student support, and support for the aged, carers and people with a disability).

As income from most sources is reported before deduction of expenses incurred in the earning of the income, these incomes are always a positive figure. However, income from some sources may be negative. Income from own unincorporated enterprise and income from rental property are collected net of expenses incurred in the raising of income, so may be negative. This may result in a negative total income.

While there is a tendency for incomes to be slightly understated in the Census, the distribution is largely consistent with that obtained from the ABS income surveys. Therefore, Census income data is useful as an indicator of relative advantage or disadvantage and economic well being.

Testing of the topic has shown that there is a general tendency for those not in the labour force to leave this question unanswered, as they consider income only applies to payments received as a result of employment. Similarly, pensioners and self funded retirees sometimes state that they receive no income as they do not regard their pension as income.

The question about Indigenous origins on the Census form asks whether each person is of Aboriginal and/or Torres Strait Islander origin. Torres Strait Islanders are the descendants of the Indigenous people of the Torres Strait, between the tip of Cape York and Papua New Guinea.

Individual incomes are collected as ranges in the Census. To enable these range values to be summed, information from the Survey of Income and Housing, which collects income as individual values, is used to estimate the median income within each bracket collected by the Census. The relevant median value for each family/household member is then summed to produce family or household income.

See also Income, Household income

Industry of employment describes the industries in which employed people aged 15 years and over work. The Australian and New Zealand Standard Industrial Classification (ANZSIC) was used in classifying the responses given to the industry questions for the 2006 Census.

The Interviewer Household Form is used in Aboriginal and Torres Strait Islander communities (and areas where language differences or other factors make use of the standard self-enumeration forms impractical). The Interviewer Household Form is an interview based Census form which is used to record the details of up to 12 persons in a household, and some dwelling data. If there are more than 12 persons in a dwelling additional Interviewer Household Forms are used. 

See also Discrete Community and Remote Areas Strategy.

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. 

Many classifications used in ABS statistics have an uneven distribution of data throughout their categories. For example, the number of people who are Anglican or born in Italy is quite large (3,679,907 and 185,403 respectively in 2011), while the number of people who are Buddhist or born in Chile (528,981 and 24,937 respectively in 2011), is relatively small. When religion is cross-classified with country of birth, the number in the table cell who are Anglican and who were born in Italy could be small, and the number of Buddhists born in Chile even smaller. These small numbers increase the risk of identifying individuals in the statistics. 

Even when variables are more evenly distributed in the classifications, the problem still occurs. The more detailed the classifications, and the more of them that are applied in constructing a table, the greater the incidence of very small cells. 

Care is taken in the specification of tables to minimise the risk of identifying individuals. In addition, a technique has been developed to randomly adjust cell values. 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. 

The counts and totals in summary tables are subjected to small adjustments. These adjustments may cause the sum of rows or columns to differ by small amounts from table totals. The counts are adjusted independently in a controlled manner, so the same information is adjusted by the same amount. However, tables at higher geographic levels may not be equal to the sum of the tables for the component geographic units.

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. 

No reliance should be placed on small cells as they are impacted by random adjustment, respondent and processing errors. 

Many different classifications are used in Census tables and the tables are produced for a variety of geographical areas. The effect of the introduced random error is minimised if the statistic required is found direct from a tabulation rather than from aggregating more finely classified data. Similarly, rather than aggregating data from small areas to obtain statistics about a larger standard geographic area, published data for the larger area should be used wherever possible. 

When calculating proportions, percentages or ratios from cross-classified or small area tables, the random error introduced can be ignored except when very small cells are involved, in which case the impact on percentages and ratios can be significant.

For Census purposes, the labour force includes people aged 15 years and over who:

• work for payment or profit, or as an unpaid helper in a family business, during the week prior to Census night;
• have a job from which they are on leave or otherwise temporarily absent;
• are on strike or stood down temporarily; or
• do not have a job but are actively looking for work and available to start work.
   

The following people are classified as being in the labour force:

• employed people (i.e. the first three groups above); and
• unemployed people (i.e. the last group above).
   

People aged 15 years and over who are neither employed nor unemployed are classified as not in the labour force. This includes people who are retired, pensioners and people engaged solely in home duties (unpaid).

In the Census the Labour Force Status variable is derived for all people aged 15 years and over. It classifies people as employed working full-time, part-time or away from work, unemployed looking for full-time work, looking for part-time work, or not in the labour force. The category 'Employed, away from work' also includes persons who stated they worked but who did not state the number of hours worked.

Labour Force Status is derived using responses to questions on:

• full/part-time job;
• job last week;
• hours worked;
• looking for work; and
• availability to start work.
   

The derivation methodology takes into account answers to these questions to derive the most appropriate Labour Force Status. 

This variable provides information on the type of landlord for rented dwellings. It applies to all households who are renting the dwelling (including caravans, etc. in caravan parks) in which they are enumerated on Census night.

Records the highest educational achievement a person aged 15 years and over has attained. It lists qualifications and other educational attainments regardless of the particular field of study or the type of institution in which the study was undertaken.

The ASGS Local Government Areas are an ABS approximation of gazetted local government boundaries as defined by each State and Territory Local Government Department. Local Government Areas cover incorporated areas of Australia. Incorporated areas are legally designated parts of a State or Territory over which incorporated local governing bodies have responsibility. The major areas of Australia not administered by incorporated bodies are the northern parts of South Australia, and all of the Australian Capital Territory and the Other Territories. These regions are identified as ‘Unincorporated’ in the ASGS Local Government Areas structure. LGA is an ASGS Non-ABS structure.

More information on local governments can be found at the Australian Local Government Association website: http://www.alga.asn.au

See Dwelling Location

A lone parent is a person who has no spouse or partner usually resident in the household, but who forms a parent-child relationship with at least one child usually resident in the household. The child may be either dependent or non-dependent.

Any private dwelling in which there is only one usual resident at least 15 years of age, is classified as being a lone person household.

The ABS present, alongside the homeless estimates from the Census, estimates of the number of people in selected marginal housing circumstances. These marginal housing groups not only provide an indication of the numbers of people living in marginal housing close to the boundary of homelessness, but can also provide a possible indication of people who may be at risk of homelessness.

Three marginal housing groups are classified from the Census:

• persons living in other crowded dwellings - those that are not in 'severely' crowded dwellings,
• persons in other improvised dwellings – that is those who were living in improvised dwellings but were not considered homeless under the rules for the group 'Persons living in improvised dwellings, tents or sleeping out'; and
• persons who are marginally housed in caravan parks.
   

The mean is calculated by summing the values of all observations in a set of data and then dividing by the number of observations in the set. Thus: mean = sum of all the observed values / number of observations.

The median is the value that divides a set of data exactly in half. It is the middle value when the values in a set of data are arranged in order. If there is no middle value (i.e. there is an even number of values) then the median is calculated by determining the mean of the two middle values. Thus: median = the middle value of a set of data.

These variables record the mortgage repayments being paid by a household to purchase the dwelling in which they were enumerated on Census night (also applicable to caravans).

The Census collects this information in single dollars up to $9,999. However, for practical purposes this information is recoded to a specific number of ranges for standard Census products.

Since 2011, Nil repayments is recorded as $0. Prior to 2011 a response of nil was coded to 'Not stated'.

A person aged 15 years or more, who is a natural, adopted, step, or foster child of a couple or lone parent usually resident in the same household, who is not a full-time student aged 15–24 years, and who has no identified partner or child of his/her own usually resident in the household.

See Type of Non-Private Dwelling.

This variable describes the level of education of the highest completed non-school qualification (e.g. Bachelor Degree, Diploma). 

The full classification for levels of education, together with an explanation of the conceptual basis of the classification, can be found in the publication Australian Standard Classification of Education (ASCED) (cat. no. 1272.0). 

Persons not in the labour force are those persons who, during the week prior to Census night, were neither employed nor unemployed. They include persons who were keeping house (unpaid), retired, voluntarily inactive, permanently unable to work, in gaol, trainee teachers, members of contemplative religious orders, and persons whose only activity during the week prior to Census night was jury service or unpaid voluntary work for a charitable organisation.

This dwelling variable provides a count of the number of bedrooms in each occupied private dwelling, including caravans in caravan parks.

Occupation information is collected in the Census for all employed people aged 15 years and over. Two questions are used in the Census:

• 'In the main job held last week, what was the person's occupation - Give full title'; and
• 'What are the main tasks that the person usually performs in the occupation...'.

Collecting both occupation title and task information ensures more accurate coding of occupations.

For 2016, targeted supplementary questions on occupation, asking more specialised questions based on the initial response, have been added to the online census forms, to provide better quality fine-level data. Common occupation responses from 2011 which were difficult to code to an appropriate level of detail, for example 'nurse', are targeted by these questions.

The 2016 Census uses the Australian and New Zealand Standard Classification of Occupations (ANZSCO), 2013, Version 1.2 (cat. no. 1220.0) to code occupation data.

See Dwelling.

Homelessness is a phenomenon becoming more prevalent among the older population, aged 55 years and over. It generally relates to the inability to maintain or find housing due to a sudden change in an older person's circumstances; such as retirement, divorce, death of a partner/spouse, affordable housing and barriers to employment.

Households living in dwellings requiring extra bedrooms according to the Canadian National Occupancy Standard (CNOS).

See Canadian National Occupancy Standard (CNOS). 

In the context of estimating homelessness overestimation occurs when persons who are represented in the underlying data set are misclassified as homeless when they are not. 

See also Undercount and/or underenumeration, Underestimation.

See Visitors to Australia.

A person identified as being in a couple relationship with another person usually resident in the same household is a partner. The couple relationship is established through reporting of either a registered or de facto marriage, and includes same-sex couples.

Any incident of sexual assault, threatened sexual assault, physical assault or threatened or attempted physical assault by a current and/or previous partner.

The Census personal form records details for one person only. It contains the same questions as the household form, but excludes the household questions. The personal form is used:

• for households with more than six people: the household form accommodates six people, so one personal form is completed for each extra person;
• for privacy: if any person in a household prefers, for privacy reasons, not to be recorded on the household form, then a personal form and a privacy envelope are issued for that person; and
• in non-private dwellings: one personal form is completed for each person in a non-private dwelling on Census night.
   

The Personal Safety Survey aims to collect information about men's and women's experience of physical or sexual assault or threat by male and female perpetrators. Experiences of the different types of violence, since the age of 15, by different types of male and female perpetrators (including current partner, previous partner, boyfriend/girlfriend or date, other known man or women, and stranger) is explored. More detailed information, such as where the incident occurred and what action was taken, can be obtained for most recent incidents of each of the different types of violence by a male and female perpetrator. Additional information is also collected about respondent experiences of current and previous partner violence such as frequency and fears of violence, incidents of stalking and other forms of harassment and general feelings of safety.

The ABS homelessness operational group for people considered to be homeless who were in improvised dwellings, tents or sleeping out on Census night. For information about rules for estimating persons in this group see 'Appendix 2: Estimation Methodology'.

The ABS homelessness operational group for people considered to be homeless who were in supported accommodation for the homeless on Census night. This includes persons staying in dwellings classified as 'Hostels for the homeless, night shelter' as well as dwellings identified through the Census 'list' strategy. Census 'list' strategy. In 2011 and 2006, there was an additional 'green sticker' strategy, whereby a physical sticker was census form in some sensitive supported dwellings. This was discontinued for 2016. 

For further information about rules for estimating persons in this group see 'Appendix 2: Estimation Methodology'.

The ABS homelessness operational group for people considered to be homeless who were staying temporarily with other households on Census night. This group also includes some people who were homeless who are in 'visitor only' households. Some people who are homeless are likely to be underestimated in this category such as youth, those escaping domestic and family violence and Aboriginal and Torres Strait Islander Australians. 

For information about rules for estimating persons in this group see 'Appendix 2: Estimation Methodology'.

The ABS homelessness operational group for people considered to be homeless who were in boarding houses on Census night. Estimation techniques are designed to take account of legal and illegal boarding houses in the estimates. As a result this category is larger than the number of people enumerated in the non-private dwellings classified as "boarding house, private hotel". For information about rules for estimating persons in this group see 'Appendix 2: Estimation Methodology'.

The ABS homelessness operational group for people considered to be homeless who had no usual address and were in other temporary lodgings: 'hotel, motel, bed and breakfast' on Census night. For information about rules for estimating persons in this group see 'Appendix 2: Estimation Methodology'.

The ABS homelessness operational group for people considered to be homeless who were living in severely crowded dwellings on Census night. This is operationalised in the Census as those people who were enumerated in a private dwelling that they were usual residents of and, according to the Canadian National Occupancy Standard (CNOS), the dwelling required four or more extra bedrooms to accommodate them. For information about rules for estimating persons in this group see 'Appendix 2: Estimation Methodology'.

See also Canadian National Occupancy Standard.

The ABS group showing people who were marginally housed in other crowded dwellings on Census night. This is operationalised in the Census as those people who were enumerated in a private dwelling that they were usual residents of and, according to the Canadian National Occupancy Standard (CNOS), the dwelling required three extra bedrooms to accommodate them. For information about rules for estimating persons in this group see 'Appendix 2: Estimation Methodology'.

See also Canadian National Occupancy Standard.

The ABS group showing people who were marginally housed. This includes people who were enumerated on Census night in the dwelling category of an 'improvised home, tent or sleepers out' who reported either being 'at home' on Census night or having no usual address, and are not considered, on balance, to be homeless. For information about rules for estimating persons in this group see 'Appendix 2: Estimation Methodology'.

The ABS group showing people who were marginally housed and living in caravan parks where they reported a usual address in a caravan, cabin or houseboat in a caravan park and are unlikely to have accommodation alternatives For information about rules for estimating persons in this group see 'Appendix 2: Estimation Methodology'.

See Country of birth.

The place of enumeration is the place at which the person is counted i.e. where they spent Census night, which may not be where the persons usually lives.

This is the place where a person usually lives. It may, or may not be the place where the person was counted on Census night.

Place of usual residence five years ago identifies a person's place of usual residence five years before the Census.

Census count of persons based on their reported place of usual residence.

A measure of the undercount in the Census is obtained from a sample survey of households undertaken shortly after the Census, called the Post Enumeration Survey (PES). It collects information about where people were on Census night and their characteristics, which are compared to the actual Census forms. The PES found an undercount of 1.0% in the 2016 Census, compared to 1.8% in 2001, 2.7% in 2006 and 1.7% in the 2011 Census.

The PES is only conducted in private dwellings therefore it cannot be used to estimate the undercount of homeless people on Census night.

See Dwelling.

Proficiency in Spoken English refers to persons who speak a language other than English at home, who report their self-assessed proficiency in spoken English. It should be regarded as an indicator of a person's ability to speak English rather than a definitive measure of his/her ability and should be interpreted with care. 

Registered Marital Status reports responses to the question 'What is the person's present marital status?' and refers to the legal status of the person, and not necessarily his/her current living arrangement. The partners in a registered marriage must be of the opposite sex as same-sex relationships could not be registered as marriages in Australia at the time of the 2016 Census. Marital status is applicable to people aged 15 years and over. 

This variable describes the relationship of each person in a family to the Family reference person or, where a person is not part of a family, that person's relationship to the Household reference person. 

Children who are usually resident in the household are classified as dependent if they form a parent-child relationship and are either 0–14 years of age; or they are 15–24 years of age and also a full-time student (in secondary or tertiary education). Children who are aged 15–24 years who are not full-time students and children aged 25 years and over are classified as non-dependent children. Children who are aged 25 years and over with a child or partner of his/her own, or who are full-time students aged 15–24 years of age with a child or partner of his/her own, are classified according to that relationship.

See Australian Statistical Geography Standard (ASGS).

The Census records the individual dollar amounts of rent paid by households on a weekly basis for the dwelling in which they were enumerated on Census night. This includes caravans etc. in caravan parks. The categories range from $0–$9,999 in single dollar amounts.

See Dwelling; Household; Usual residence.

The Census records whether people enumerated in non-private dwellings (such as motels, hospitals, colleges etc.) are staying there as either: members of staff of the accommodation (e.g. owner, proprietor, porter, cook, teacher, warden, family of owner or family of staff); or residents, guests, patients, inmates, etc.

No information on family relationships is available for people in non-private dwellings because they are numerated using personal forms. 

The 2016 Census of Population and Housing aims to count every person who spent Census night, 9 August 2016, in Australia. This includes people in the six states, the Northern Territory, the Australian Capital Territory, Jervis Bay Territory, and the Territories of Christmas Island and Cocos (Keeling) Islands and Norfolk Island. The other Australian external territories (minor islands such as Heard and McDonald Islands), are outside the scope of the Australian Census. 

People who leave Australia but who are not required to undertake migration formalities, for example those on oil and gas rigs off the Australian coast, and expeditioners to Australian bases in the Australian Antarctic Territory (and other locations) are included in the Census. They are coded to an Off-Shore Statistical Areas Level 1 in Tasmania.

Visitors to Australia are included regardless of how long they have been in the country or how long they plan to stay. The only groups of people who spend Census night in Australia but are excluded from the Census are foreign diplomats and their families, this derives from the Vienna Convention. In practice, a diplomat is defined as someone entitled to travel on a diplomatic passport. Foreign crew members on ships who remain on the ship and do not undertake migration formalities are also out of scope of the Census.

All private dwellings, except diplomatic dwellings, are included in the Census, whether occupied or unoccupied. Caravans in caravan parks and manufactured homes in manufactured home estates, are counted only if they are occupied. Occupied non-private dwellings, such as hospitals, prisons, hotels, etc. are also included, however unoccupied non-private dwellings are out of scope. Unoccupied residences of owners, managers or caretakers of such establishments are counted.

For more detail see Census of Population and Housing - Census Dictionary (cat. no. 2901.0).

Self-enumeration is the term used to describe the way Census data are collected. The Census forms are generally completed by householders (or individuals in non-private dwellings) rather than by interviewers, although Interviewers are available in some areas.

The sex of each person enumerated in the Census is recorded as being either male or female.

See Dwelling Structure.

The Index of Relative Socio-Economic Disadvantage (IRSD) is a general socio-economic index that summarises a wide range of information about the economic and social resources of people and households within an area. Because this index focuses on disadvantage, only measures of relative disadvantage are included. This means that a high score (or decile) reflects a relative lack of disadvantage rather than relative advantage.

This index summarises 17 different measures, such as low income, low education, high unemployment and unskilled occupations. A low score indicates relatively greater disadvantage in general. For example, an area could have a low score if there are (among other things) many households with low income, many people with no qualifications, or many people in low-skilled occupations.

A high score indicates a relative lack of disadvantage in general. For example, an area may have a high score if there are (among other things) few households with low incomes, few people with no qualifications or in low-skilled occupations.

The Specialist Homelessness Services (SHS) collection obtains information about people, adults and children, who seek assistance from specialist homelessness agencies. Services can include accommodation provision, assistance to sustain housing, domestic/family violence services, mental health services, family/relationship assistance, disability services, drug/alcohol counselling, legal/financial services, immigration/cultural services, other specialist services and general assistance and support.

This collection is complied by the Australian Institute of Health and Welfare (AIHW). This collection only includes organisations that receive government funding to deliver specialist homelessness services, and can be either not-for-profit or for profit agencies.

This collection replaces the Supported Accommodation Assistance Program (SAAP) National Data Collection in 2001.

See also Australian Institute of Health and Welfare

See Partner.

States/Territories are the largest spatial unit in the ASGS and are part of the Main Structure within ABS Structures. There are six states and six territories in the ASGS:

• New South Wales
• Victoria
• Queensland
• South Australia
• Western Australia
• Tasmania
• Northern Territory
• Australian Capital Territory
• Jervis Bay Territory
• Territory of Christmas Island
• Territory of the Cocos (Keeling) Islands and
• Territory of Norfolk Island.

These spatial units are political entities with fixed boundaries. In aggregate, they cover Australia without gaps or overlaps.

See also Australian Statistical Geography Standard (ASGS).

The Statistical Area Level 1 (SA1) is the second smallest geographic area defined in the ASGS, the smallest being the Mesh Block. SA1s are built from whole Mesh Blocks. Whole SA1s aggregate directly to SA2s in the ASGS Main Structure.

The SA2s are a general-purpose medium-sized area built from whole SA1s. Their aim is to represent a community that interacts together socially and economically. Whole SA2s aggregate directly to SA3s in the Main Structure. SA2s do not cross State and Territory borders. In aggregate, they cover the whole of Australia without gaps or overlaps. 

The SA3s provide a standardised regional breakup of Australia. The aim of SA3s is to create a standard framework for the analysis of ABS data at the regional level through clustering groups of SA2s that have similar regional characteristics. SA3s are built from whole SA2s and aggregate directly to SA4s in the Main Structure.

The SA4 regions are the largest sub-State regions in the Main Structure of the ASGS. They are designed for the output of labour force data and reflect labour markets within each State and Territory within the population limits imposed by the Labour Force Survey sample. SA4s provide the best sub-state socio-economic breakdown in the ASGS and in rural areas generally represent aggregations of multiple small labour markets with socioeconomic connections or similar industry characteristics. SA4s are built from whole SA3s and aggregate directly to States and Territories in the Main Structure.

See Full/Part-Time student status.

The Supported Accommodation Assistance Program (SAAP) was established in 1985 to consolidate a number of Commonwealth, State and Territory government programs assisting people experiencing homelessness and those at risk of homelessness, including women escaping domestic violence. 

In 2011, the SAAP collection was replaced with the Specialist Homelessness Services (SHS) collection. 

The Survey of Disability, Ageing and Carers (SDAC) aims to measure the prevalence of disability in Australia and levels of support needed, as well as providing a demographic and socio-economic profile of people with disability and older people (65 years and over) compared with the general population. It also provides information about people who provide care to older people and people with disability.

The Census form seeks information about people who usually reside in a dwelling but who are temporarily absent on Census night.

See Dwelling Structure.

Tenure Type describes whether a household is purchasing, rents or owns, the dwelling in which it was enumerated on Census night, or whether the household occupies it under another arrangement. Tenure Type is derived from the responses to a series of questions. It is applicable to all occupied private dwellings.

See State and Territory.

People identified as being of Torres Strait Islander origin. May also include people identified as being of both Torres Strait Islander and Aboriginal origin.

The 2011 Census records the type of educational institution being attended by people who are full/part-time students. The categories cover pre-school through to tertiary institutions.

This variable records the type of non-private dwelling in which people were enumerated on Census night. Non-private dwellings are establishments which provide a communal type of accommodation. Examples of the information collected are: Hotel, motel; Boarding house, private hotel; Public hospital (not psychiatric); and Child care institution. 

Hotels and private hotels are categorised differently within Type of Non-Private Dwelling (NPDD). This is mainly because of differences in length of residency, service provision, and how the hotel/private hotel classifies itself. 

There has been a change in the way this information is collected. In 2016, it was recorded by ABS Address Canvassing Officers in the lead up to the Census as part of establishing the Address Register as a mail-out frame for designated areas. In areas enumerated using the traditional approach of delivering forms, the information was collected by ABS Field Officers during the Census collection period. Type of non-private dwelling data was also updated as required by ABS Field Officers during the 2016 Census enumeration period.

Although extensive efforts are made to contact all occupied dwellings and count all unoccupied private dwellings in the Census, locating and contacting them all is not possible. Some dwellings may not be identified. For example, flats above or behind shops or attached to private dwellings may not be included in the Census. Analysis of the undercount in previous Censuses has shown that people away from their usual residence on Census night (for example, travelling, camping, staying in a non-private dwelling, or visiting friends) are more likely to be missed than people at home on Census night. 

Even when a household is contacted, undercount is possible if not all members of the household can be included on the form (six people can be recorded on the paper form and ten on the online form) no extra online or paper forms are obtained. Undercount is also possible if the household, or a member of the household, refuses to cooperate and complete a Census form. A measure of the extent of underenumeration is obtained from the Post Enumeration Survey (PES). The official population estimates produced by the ABS take into account the results of the PES. However, the Census counts are not adjusted.

A measure of the extent of underenumeration is obtained from the Post Enumeration Survey (PES). The official population estimates produced by the ABS take into account the results of the PES. However, the Census counts are not adjusted. The PES is only conducted in private dwellings therefore it cannot be used to estimate the underenumeration of homeless people on Census night.

See also Post Enumeration Survey (PES).

The difficulty in isolating unique characteristics of the homeless population within the Census of Population and Housing can result in the misclassification of homeless persons, and subsequent underestimation of the homeless population. The complexity and diversity of persons homeless experiences, and person's not identifying themselves as homeless, increases the likelihood of underestimation of homelessness in particular groups, including Youth, Aboriginal and Torres Strait Islander peoples', and people escaping domestic and family violence. 

See Labour force status.

See Dwelling.

Census collects information from persons aged 15 years and over, separate from the labour force questions and covers the following topics:

• voluntary work through or for an organisation or group in the previous twelve months;
• caring for a person who has a disability, a long-term illness or problems related to old age in the previous two weeks;
• caring for a child aged less than 15 years (including own child) in the previous two week;s and
• domestic work for own household in the previous week.
   

Usual address information is used to code usual residence.

See Usual residence.

Usual residence data provide information on the usually resident population of an area, and on the internal migration patterns at the state and regional levels. The 2011, 2006 and 2001 Censuses had three questions on usual residence that asked where the person usually lived on Census night, and where the person usually lived one year ago and five years ago.

Family variables 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. 

For the purposes of homelessness estimation and estimating marginal housing, visitor only households are those dwellings where all persons in the dwelling reported no usual address and there were no usual residents.

See also Visitors to a household, Usual residence.

Characteristics of individual visitors to a household are available at the household of enumeration. Visitors may also be tabulated according to their Statistical Area Level 1 (SA1) of usual residence but cannot be placed back to their dwelling of usual residence. For the 2016 Census, data is imputed to SA1 level where the respondent has given insufficient address information. Visitors are excluded from household and family classifications, although counts of visitors (and visitor only households) are still available separately. 

All household and family classifications in the Census are based on the relationships of people usually residing in the household. This applies when there is at least one person aged 15 years and over present. In these classifications, people temporarily absent are included, and visitors are excluded. The relationship of visitors to one another, or to any resident (including cases where all the people enumerated are visitors) is not further classified. 

The question on the Census form, 'Where does the person usually live?' allows the identification of people who are usually resident in another country.

See also Place of enumeration, Place of Usual Residence.

See Unpaid Work

Provides an indicator of the gross income (including pensions and allowances) that persons aged 15 years and over usually receives each week. 

Census collects the year of arrival in Australia for people born overseas who intend staying in Australia for at least one year. In 1996, data were collected in categories ranging from 'Before 1981' to '1996'. From 2001 onwards, data were collected by single year with valid responses in 2011 being in the range 1895 to 2011. For 2016, data are collected by single year with valid responses in the range 1900 to 2016.

Youth homelessness refers to those homeless youths aged between 12 and 24 years. This group is of interest as intervention (while in supported accommodation) with education and training programs leads to enduring housing outcomes. Some researchers define youth as aged 12–18 years. They may even dissect the age groups into 12–15,16–18 and 19–24 years due to the different characteristics of each, revolving around education and training, and labour force.

For information on the institutional environment of the Australian Bureau of Statistics (ABS), including the legislative obligations of the ABS, financing and governance arrangements, and mechanisms for scrutiny of ABS operations, please see the ABS Institutional Environment.

This publication presents estimates of the prevalence of homelessness and the characteristics and living arrangements of those likely to be homeless on Census night 2016. Estimates are also provided for people whose living arrangements are close to the statistical boundary of homelessness, but who are not classified as homeless. As homelessness itself is not a characteristic that is directly collected in the Census, estimates are derived from Census data using analytical techniques. Prevalence estimates (of how many people experienced homelessness at a particular point-in-time) enable analysis of the scale of homelessness, and can be used to report trends and to target services to prevent or ameliorate the circumstances of homelessness through knowing both the locations of the homeless and their characteristics. The ABS definition of homelessness underpins the methodology used to compile the ABS estimates of homelessness. An overview of the definition is provided in 'Appendix 1 - Definition of Homelessness'.

The Census and Statistics Act 1905 requires the Australian Statistician to conduct a Census on a regular basis. Since 1961, a Census has been held every 5 years. The 2016 Census was the 17th national Census, and was held on the 9th August 2016. Data on homelessness have been collected in varying forms in the Census since 1933.

Results for the Census of Population and Housing: Estimating Homelessness were released March 2018 with similar timing to other analytical products from the Census, including the Australian Census Longitudinal Dataset.

To understand the accuracy of homelessness estimates, it is important to understand the quality of Census data. While homelessness itself is not a characteristic that is directly collected in the Census of Population and Housing, estimates of the homeless population are derived from the Census using analytical techniques based on both the characteristics observed in the Census and assumptions about the way people may respond to Census questions.

The ABS implemented a targeted strategy to assist in enumerating people experiencing homelessness during the 2016 Census and to improve the accuracy of data collected from this group. The accuracy of Census data is detailed in Census of Population and Housing: Understanding the Census and Census Data, Australia (cat. no. 2900.0) including specific statements for each data item that include the non-response rate and other important contextual information.

The first official ABS estimates of the prevalence of homelessness were published in 2012. Census of Population and Housing: Estimating homelessness, 2006 (cat. no. 2049.0) (published in 2012) presents estimates using data from the 2001 and 2006 censuses. Census of Population and Housing: Estimating homelessness, 2011 (cat. no. 2049.0) presents data using data from the 2011 Census.

The estimates use the ABS methodology for estimating homelessness from the Census. For more information, see the Information Paper - Methodology for Estimating Homelessness from the Census of Population and Housing (cat. no. 2049.0.55.001).

There are small changes and improvements in the methodology over time which may affect the ability to compare intercensal estimates. These are detailed in 'Appendix 2 - Estimation Methodology'. A change in the treatment of boarding houses for the 2016 release has been applied to the 2011 data, and revised figures are available in this publication.

The 'Explanatory notes' section of this publication (cat. no. 2049.0) should also be referred to as it includes further information on survey methods and design, comparability with previous surveys and summary results.

Tabulated data are freely available in Excel spreadsheets which can be accessed from the 'Data downloads' section of this publication.

Customised data are also available on request. Note that detailed data will be assessed for disclosure risk which in some cases may result in data being regarded as unfit for release.

A Survey TableBuilder product: Microdata: Census of Population and Housing: Estimating homelessness (cat. no. 2049.0.55.002) will be produced, subject to the approval of the Australian Statistician. For further details, refer to the Microdata Entry Page on the ABS website. It is expected that this will be released in mid-2018.

For further information about these or related statistics, contact the National Information and Referral Service on 1300 135 070, or email client.services@abs.gov.au. The ABS Privacy Policy outlines how the ABS will handle any personal information that you provide to needs, discuss options, and provide you with an obligation free quote.