Extended family type 2013 Census (information about this variable and its quality)

##Where the data comes from

The key questions from which this variable is derived are questions 6 (relationship to reference person) and 21 (absentee relationship to reference person) on the dwelling form and question 19 (living arrangements) on the individual form.

##How this data is classified

1 One-generation extended family

2 Two-generation extended family

3 Three or more generation extended family

9 Extended family not classifiable

For further information about this classification, refer to the 2013 Census data dictionary.

For background information on classifications and standards, refer to the Classifications and related statistical standards page.

##Subject population

The subject population for this variable is extended families in private occupied dwellings.

The subject population is the people, families, households, or dwellings to whom the variable applies.

##Non-response and data that could not be classified

This is a derived variable. However 0.1 percent of extended family types were classified as 'Extended family not classifiable' in 2013, compared with less than 0.1 percent in 2006 and 0.3 percent in 2001.

Extended family type has a minimal 'Not classifiable' rate, as this classification only occurs when an extended family has been identified but it is not possible to determine the generational span. In general, if enough information has been provided to determine that an extended family is present, the generational span can also be determined.

In some cases there may not be sufficient information to identify that an extended family was present. In this instance, the extended family will not have been included in this data.

##How this data is used

Data from family and household variables is used 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
• Statistics NZ to derive household and family projections.

##Data quality processes

All census data was checked thoroughly during processing and evaluation, to ensure that it met quality standards and is suitable for use. These quality checks included edits.

All data must meet minimum quality standards to make it suitable for use.

Quality level

A quality level is assigned to all census variables: foremost, defining, or supplementary.

Extended family type is a defining variable. Defining variables cover key subject populations that are important for policy development, evaluation, or monitoring. These variables are given second priority in terms of quality, time, and resources across all phases of a census.

Mode of collection impacts – online form compared with paper form

The online forms had built-in editing functionality that directed respondents to the appropriate questions and ensured that their responses were valid. As a result of this, data from online forms may be of higher overall quality than data from paper forms. The significance of this will depend on the particular type of analysis being done. There will always be a mode effect but this cannot be measured. Statistics NZ design and test to minimise the effects of mode for all questions.

There were differences between how the forms were completed online and on paper for this variable:

• On the online form, only one response could be selected for each person's relationship to the reference person in questions 6 and 21 on the dwelling form. Multiple responses for a person's relationship to the reference person were possible when forms were completed on paper.
• For the living arrangements question, the online form did not allow inconsistent multiple responses of 'I live alone' to be selected at the same time as one or more responses indicating people with whom the respondent lived. If the 'I live alone' box was marked, any other response options to the living arrangements question disappeared. Inconsistent multiple responses to this question were possible when forms were completed on paper.

##Quality assessment of data and data quality issues for this variable

Overall quality assessment

High: fit for use – with minor data quality issues only. 2013 Census variable quality rating scale gives more detail.

Issues to note

• While the number of extended families that could not be classified is very low, some extended families may not have been counted at all due to incorrect (due to respondent error) or incomplete family coding (ie it could not be determined if an individual was part of, or related to the family).

##Comparing this data with previous census data

This data is fully comparable with data from the 2006 and 2001 Censuses. Changes in the data over this time period can be interpreted as real changes because there have been no changes in the way the data has been collected, defined, and classified.

##Comparing this data with data from other sources

Census is the only information source that provides comprehensive information for small areas and small populations. However alternative sources of information about this subject are available:

• Household Labour Force Survey (HLFS).

Data from these alternative sources may show differences from census data for several reasons. These could be due to differences in scope, coverage, non-response rates, data being collected at different periods of time, alternative sources being sample surveys and as such subject to sampling errors, or differences in question wordings and method of delivery (self-administered versus interviewer-administered). Data users are advised to familiarise themselves with the strengths and limitations of individual data sources before comparing with census data.

##Further information about this data

When using this data, be aware of the following:

• During census processing, the people in each private dwelling (including absentees) have codes allocated to them that indicate who they live with and their roles within families (eg partner, parent, child). The extended family type derivation uses the family coding to identify the generational span of related people within households and to determine the extended family type of each extended family.
• Households consisting only of grandparents and grandchildren (who have been classified as children in a family nucleus with their grandparents in a parental role) are not included in the extended families data. This is because they form just one family nucleus and there are no 'Other related people'. They are included in the family type data.
• There has been no significant change to the extended family data that can be attributed to the longer than usual time period between censuses.
• For information on extended family income, please see Information by variable – Total income.

Contact our Information Centre for further information about using this variable.