Quality Statement
An extended family is a group of related people who usually reside together:
- either as a family nucleus with one or more other related people, or
- as two or more related family nuclei, with or without other related people.
Included are people who were absent on census night but usually live in a particular dwelling and are members of that extended family; generally, these will be people reported as being absent on the online household set-up form or paper dwelling form and are away from New Zealand for less than 12 months.
The concept contains one variable, extended family type.
Extended family type: Moderate quality
Data quality processes section below has more detail on the rating.
Priority level 2
A priority level is assigned to all census concepts: priority 1, 2, or 3 (with 1 being highest and 3 being the lowest priority). Priority 2 concepts cover key subject populations that are important for policy development, evaluation, or monitoring. These concepts are given second priority in terms of quality, time, and resources across all phases of a census.
The census priority level for extended family type remains the same as 2018.
The 2023 Census: Final content report has more information on priority ratings for census concepts.
Extended family type: Extended families in occupied private dwellings
‘Subject population’ means the people, families, households, or dwellings that the variable applies to.
Extended family type is classified into the following categories:
Census Classification of Extended Families V1.0.0 - Level 1 of 1
| Code | Category |
|---|---|
| 1 | One-Generation Extended Family |
| 2 | Two-Generation Extended Family |
| 3 | Three- or More Generation Extended Family |
| 9 | Extended Family not Classifiable |
Extended family type uses a 1-level flat classification as presented in the table above. Follow the link above the table to examine the classification and find more detail.
The criteria used to place an extended family into the classification is the number of generations present, and if two are present, whether they are adjacent or not. If two adjacent generations are present, the family is classified as a two-generation extended family. If two non-adjacent generations are present, the family is classified as a three- or more generation extended family.
The 2023 Census classification for extended family type is consistent with level 1 of the classification that was used in the 2018 Census (New Zealand Standard Classification of Extended Families V1.0.0). Level 2 of the classification was not used for census output.
Standards and classifications has more information on what classifications are, how they are reviewed, where they are stored, and how to provide feedback on them.
Extended families is derived from information about the people who usually live in the household: usual residence (question 5 on the individual paper form), living arrangements (question 17 on the individual paper form) and relationship to reference person (questions 18 and 21 on the dwelling paper form).
For more information on question format for households, families, extended families, see Count of families and households – 2023 Census: Information by concept.
Stats NZ Store House has samples for both the individual and dwelling paper forms.
Data-use outside Stats NZ:
- by central government agencies, local authorities, private organisations, and researchers in the formulation of social policy, for planning and monitoring programmes, and for research purposes.
- by the Ministry of Social Development in their social report, and production of derived statistics.
- by Te Puni Kokiri in their housing data.
Data-use by Stats NZ:
- used to produce family estimates and projections.
Data sources for individuals included in families and households are from either census responses or admin enumerated records in occupied private dwellings.
The data source for households and families can be from census responses only, admin enumerations only, or a mixture of both census responses and admin enumerations. Methodology for using admin data to count people in the 2023 Census has more information about admin enumeration.
Blank households are private dwellings containing no census respondents or admin enumerations, but where a household of usual residents would be expected.
| Data sources used to derive family and household data – households in occupied private dwellings | |
|---|---|
| Source of household counts | Percent |
| Household from Census forms | 92.3 |
| Admin enumerated household | 3.1 |
| Household from both Census forms and admin enumeration | 1.2 |
| Blank household | 3.5 |
| Total | 100.0 |
| Note: Due to rounding, individual figures may not always sum to the stated total(s). | |
For admin enumerated records and where information from census forms was missing, relationship information from historical census data and admin data was used. Sources of admin relationship information include:
- Department of Internal Affairs births, deaths, marriages, and civil unions
- Ministry of Business, Innovation and Employment visa applications
- Ministry of Social Development partnership and child data
- Working for Families tax return details.
For the purposes of family and household coding for the 2023 Census, admin relationships were restricted to partners, parents, children, siblings, grandparents and grandchildren.
Missing and residual responses represent data gaps where respondents either did not provide answers (missing responses) or provided answers that were not valid (residual responses).
Where possible, alternative data sources have been used to fill missing and residual responses in the 2023 and 2018 Censuses.
There are no non-response categories for extended family type. Without census response or admin enumeration of usual residents into a dwelling, relationships cannot be formed, and family variables cannot be derived.
Where extended families are identified, but the generations are unable to be determined, they are categorised as ‘extended family type not classifiable’.
Percentage of ‘extended family type not classifiable’ for extended families in occupied private dwellings:
- 2023: 0.1 percent
- 2018: 0.1 percent
- 2013: 0.1 percent.
'Families and Households in the 2023 Census: Data sources, methodology and data quality' will have more information on missingness in household and family data. A link to the paper will be available in late 2024.
Overall quality rating for extended family type: Moderate
Data has been evaluated to assess whether it meets quality standards and is suitable for use.
Three quality metrics contributed to the overall quality rating:
- data sources and coverage
- consistency and coherence
- accuracy of response.
The lowest rated metric determines the overall quality rating.
Data quality assurance in the 2023 Census provides more information on the quality rating scale.
Data sources and coverage: High quality
The quality of all the data sources that contribute to the output for the variable have been assessed. To calculate a data sources and coverage quality score for a variable, each data source is rated and multiplied by the proportion it contributes to the total output.
The rating for a valid census response is defined as 1.00. Ratings for other sources are the best estimates available of their quality relative to a census response. Each source that contributes to the output for that variable is then multiplied by the proportion it contributes to the total output. The total score then determines the metric rating according to the following range:
- 98–100 = very high
- 95–<98 = high
- 90–<95 = moderate
- 75–<90 = poor
- <75 = very poor.
The main data source for extended family type is the household matrix; therefore, the data sources for the matrices are used to calculate the metric 1 rating for extended family type. The sources of data for the matrix of a household are the units that make up the household, that is, whether the household is made up of census responses only, admin enumerations only, a mixture of both census responses and admin enumerations or is a blank household that has no individual unit sources (usual residents).
The proportion of households from census forms, low proportions from admin enumeration and mixed households, and low proportions of blank households resulted in a score of 0.96 leading to the quality rating of high.
| Data sources and coverage rating calculation for households in occupied private dwellings, 2023 Census | |||
|---|---|---|---|
| Source | Rating | Percent | Score contribution |
| Household from census forms | 1.00 | 92.27 | 0.92 |
| Admin enumerated household | 0.76 | 3.09 | 0.02 |
| Household from both census forms and admin enumeration | 1.00 | 1.17 | 0.01 |
| Blank household | 0.00 | 3.47 | 0.00 |
| Total | 100.00 | 0.96 | |
| Note: Due to rounding, individual figures may not sum to the stated totals(s) or score contributions | |||
Consistency and coherence: High quality
Extended family type is consistent with expectations across nearly all consistency checks, with some minor variation from expectations or benchmarks which makes sense due to real-world change, incorporation of other sources of data, or a change in how the variable has been collected.
Minor variation from expectations, specifically the increase in two and three- or more generation extended families, are attributable to real world change (more people living in multi-generational and larger households), and the improved processing of household matrices.
Accuracy of responses: Moderate quality
Accuracy of responses were assessed through the quality of the methods for completing the relationships in the household matrices and also analysis of people missing from households.
Extended family type data has various data quality issues involving several categories or aspects of the data, or an entire level of a hierarchical classification. The data quality issues could include problems with the classification or coding of data, such as vague responses resulting in coding issues, or responses that cannot be coded to a specific (non-residual) category, therefore reducing the amount of useful, meaningful data available for analysis.
Extended family type is lower quality than some other families and household data due to the size and complexity of households that tend to contain extended families.
There were significant changes introduced in the 2023 Census that impacted the quality of household matrices and therefore the quality of household variables. These were:
- improvements in the methodology for using admin relationships to construct families and households when census relationships were missing
- more extensive checks for errors, and higher quality manual corrections for households that had errors due to a dedicated and larger family coding manual intervention team
- higher quality repatriation of people to the dwelling they usually live in.
'Families and Households in the 2023 Census: Data sources, methodology and data quality' will have more information on the data quality of household and family data. A link to the paper will be available in late 2024.
It is recommended that the extended family type data can be used in a comparable manner to the 2013 and 2018 Censuses.
When using this data, users should be aware that:
- There is a notable increase in the count of extended families compared to 2018 due to improved admin enumeration into dwellings and real-world changes such as increased living costs.
- Not all people counted in the census usually resident population are part of the derivation of households and families, e.g. people who were admin enumerated at a meshblock rather than a dwelling level and people living in non-private dwellings. In addition, there are dwellings that were not occupied at the time of the census or not counted in the census. This means there will be families, extended families and households that are not counted in census outputs.
- Care should be taken when looking at the time series as there were changes to the collection strategy, processing system, and household and family coding methodology between the 2013 and 2018 Censuses, and further improvements made to these for the 2023 Census. These improvements mean household and family data is of a higher quality in the 2023 Census compared to previous censuses.
- The quality of relationships within households in the 2023 Census is higher than in previous censuses, including for more complex households and households containing at least one member of the Māori or Pacific Peoples ethnic groups.
- There are fewer unclassifiable extended families compared to the 2018 Census, due to several new consistency edits and increased manual intervention.
- When conducting time series analysis be aware of the undercount of two-generation extended families in the 2018 Census. This issue has been resolved in the 2023 Census.
'Families and Households in the 2023 Census: Data sources, methodology and data quality' will have more information on reco changes to the methodology and data quality of household and family data. A link to the paper will be available in late 2024.
To assess how the 2023 data for this concept aligns with the data from the previous censuses, use the links:
- Families and households: extended family type - 2018 Information by variable
- Extended family type - 2013 Information by variable
Contact our Information centre for further information about using this concept.
