2900.0 - Census of Population and Housing: Understanding the Census and Census Data, Australia , 2016  
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Child Type (including grandchildren) (CTGP)

This variable records the different parent-child relationship within families. It differs from the standard Child Type variable in that it recognises grandparent-grandchild relationships as parent-child relationships, regardless of the age of the grandchild. It is applicable to all children.

How this variable is created

In the 2016 Census, data on the relationships people have with others in the same dwelling is mainly derived from the Relationship in Household question on the Census Household Form, which asks for each person’s relationship to Person 1 on the form. An image of this question is provided below.

Variable history

Child Type (including grandchildren) was created in 2011. No changes were made for 2016.

Non-response rate

Non-response rate only applies to data items that directly reflect responses to individual Census form questions. Child Type (including grandchildren) does not have a non-response rate as it is a derived value created during Census processing for applicable persons. For more information, refer to Understanding Census data quality.

Data usage notes

Grandparent families are recognised where there is a grandparent-grandchild relationship present and no parent-child relationship present in a family. Where a parent is temporarily absent from the family, and their relationship reported does not confirm their relationship to their child (for example, if person 1 is not a member of their family nucleus) that parent-child relationship cannot be coded. This can result in a small number of children being reported as grandchildren when a parent is simply absent on Census night.

Users should note that grandparent-grandchild relationships are constructed for the purposes of family coding in order to create a statistical family. It may not be representative of who provides care, for example a grandparent caring for their grandchild or vice versa.

There are three variables in Census data that describe grandparent/grandchild relationships. These are shown in the table below with reference to the standard Census variables.


Standard variablesGrandparent variables

RLHP (Relationship in Household)RLGP (Relationship in Household, including grandchildren)
FMCF (Family Composition)FMGF (Grandparent Families)
CTPP (Child Type)CTGP (Child Type, including grandchildren)


While the standard and grandparent variables are similar, there are differences in the way data is processed. The table below shows how grandparent/grandchild relationships are classified under the standard variables compared with the grandparent variables.

Standard variablesGrandparent variables

Person aged 15 years or more and has relationship of grandchildPerson is classified as 'other relative'.Person is classified as a 'type of child' with a relationship of dependent student' or 'non-dependent child'.
A sole grandparent in the familyFamily is classified as 'other family'.Family is classified as 'lone parent'.
A grandparent coupleFamily is classified as 'couple family with no children and with relatives'.Family is classified as 'couple family with children'.


Due to these differences, Child Type (including grandchildren) should only be used in conjunction with other related grandparent/grandchild classifications.

Further information

A definition for Child Type (including grandchildren) is available in the 2016 Census Dictionary.
For more related information for Child Type (including grandchildren), see data quality statements Child Type, Relationship in Household, Relationship in Household and Grandparent Families.

Household form question image

Question 5 as it appeared on the 2016 Census Household Paper Form:

Image: 2016 Household Paper Form - Question 5. What is the person's relationship to Person 1/Person 2?
A text only version of the online Census Household form is available from the Downloads tab.