Quality Statement
The Māori descent concept defines if a person is of Māori descent, not of Māori descent, or does not know if they are of Māori descent. A person is of Māori descent if they are descended from Māori.
Māori descent is based on a genealogical or biological concept. For the purposes of the Māori descent classification, having Cook Island Māori ancestry is not classified as being of Māori descent.
Some adjustments have been applied to the responses to the Māori descent question in instances where there was no response or where the response is not ‘Māori descent’ or ‘No Māori descent’. The purpose of the adjustments is to obtain a ‘Māori descent’ or ‘No Māori descent’ value for every person in the census usually resident population count, as every person needs to be assigned to be either of Māori descent or not.
Very high quality
Data quality processes section below has more detail on the rating.
Priority level 1
A priority level is assigned to all census concepts: priority 1, 2, or 3 (with 1 being highest and 3 being the lowest priority).
Māori descent electoral is a priority 1 concept. Priority 1 concepts are core census concepts that have the highest priority in terms of quality, time, and resources across all phases of a census.
The priority level for Māori descent electoral remains the same as 2018.
The 2023 Census: Final content report has more information on priority ratings for census concepts.
Census usually resident population count
‘Subject population’ means the people, families, households, or dwellings that the variable applies to.
Māori descent electoral is classified into the following categories:
Census Māori Descent electoral V1.0.0 – Level 1 of 1
Code | Category |
---|---|
1 | Māori Descent |
2 | No Māori Descent |
Māori descent electoral uses a 1-level flat classification with level 1 presented in the table above. Follow the link above the table to examine the classification and find more detail.
The 2023 Census classification for Māori descent electoral is consistent with that used in 2018 Census. This is a separate classification to Māori descent.
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.
Māori descent data is collected from the individual form (question 12 paper form).
The wording for the 2023 Census changed from ‘Are you descended from a Māori?’ to ‘Are you descended from Māori?’ as respondents found the original wording awkward and ungrammatical. Other Stats NZ household surveys have also updated this question to remove the ‘a’.
The modes of collection (online and paper forms) had different ways a person could respond.
On the online form:
- Māori descent was a mandatory variable requiring a single response for the respondent to submit the form
- built-in routing functionality directed all individuals who were usually resident in New Zealand at the time of the census to this question.
On the paper form:
- respondents could skip the question, or tick multiple boxes resulting in a missing or residual response.
Data from the online forms may therefore be of higher overall quality than data from paper forms. However, processing checks and edits were in place to improve the quality of the paper form data.
Stats NZ Store House has samples for both the individual and dwelling paper forms.
Data-use by Stats NZ:
- in conjunction with Māori electoral option data to calculate the Māori electoral population and determine the number of Māori electorates
- to derive the estimated resident population of Māori descent.
Alternative data sources were used for missing and residual census responses and responses that could not be classified or did not provide the type of information asked for. This is an extension of the methodology for the collection of Māori descent in the 2018 Census. The table below shows the distribution of data sources for Māori descent electoral data.
Data sources for Māori descent electoral data, as a percentage of census usually resident population count, 2023 Census | ||
---|---|---|
Source of Māori descent electoral data | Percent | |
2023 Census response | 83.0 | |
Historical census | 10.5 | |
2018 Census | 7.5 | |
2013 Census | 3.0 | |
Admin data | 4.0 | |
Parental data | 0.2 | |
Deterministic derivation | 0.1 | |
Statistical imputation | 2.2 | |
CANCEIS(1) donor’s response sourced from 2023 Census form | 0.9 | |
CANCEIS donor’s response sourced from 2018 Census | 0.7 | |
CANCEIS donor’s response sourced from 2013 Census | 0.3 | |
CANCEIS donor’s response sourced from admin data | 0.3 | |
CANCEIS donor’s response sourced from parental data | <0.1 | |
No information | 0.0 | |
Total | 100.0 | |
1. CANCEIS = imputation based on CANadian Census Edit and Imputation System. Note: Due to rounding, individual figures may not always sum to the stated total(s) or score contributions. |
The alternative data sources for Māori descent electoral were the same as Māori descent output. For Māori descent electoral, alternative data sources were used to assign responses of ‘Don’t know’ as either ‘Māori descent’ or ‘No Māori descent’.
Where appropriate, responses were used from the 2018 and 2013 Censuses to replace ‘Don’t know’, missing, or residual responses. When this was not possible, the following admin data sources were used:
- Department of Internal Affairs (DIA) Births Register
- Electoral Commission electoral roll.
Electoral roll data was introduced as an admin data source for the first time in the 2023 Census.
If it was not possible to obtain Māori descent electoral information from historical census data or admin data, ‘parental’ data was used. This is where Māori descent values for parents or grandparents can be used to fill missing information on Māori descent for their children or grandchildren.
If a value for Māori descent electoral is still missing, deterministic derivation is used. This is when a valid iwi value on the 2023 Census form, historical census data, or admin data is used to confirm Māori descent.
Statistical imputation was used for any records that remained coded to ‘Don’t know’, ‘Not stated’, or other residual categories.
Editing, data sources, and imputation in the 2023 Census describes how data quality is improved by editing, and how missing and residual responses are filled with alternative data sources (admin data and historical census responses) or statistical imputation. The paper also describes the use of CANCEIS (the CANadian Census Editing and Imputation System), which is used to perform imputation. This webpage also contains a spreadsheet that provides additional detail on the admin data sources.
Data sources and imputation for Māori descent in the 2023 Census provides more detailed explanations about the methodology and changes from the 2018 Census.
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.
In all censuses since 1996, Māori descent electoral has not contained any missing or residual responses. Adjustments were applied to the data to ensure all residents enumerated in the previous censuses were assigned as either ‘Māori descent’ or ‘No Māori descent’.
Overall quality rating: Very high
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 responses.
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: Very high quality
The quality of all the data sources that contribute to the output for the variable have been assessed. To calculate the data sources and coverage quality score for a variable, each data source was 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 ranges:
- 0.98–1.00 = very high
- 0.95–<0.98 = high
- 0.90–<0.95 = moderate
- 0.75–<0.90 = poor
- <0.75 = very poor.
The high proportion of data received from 2023 Census forms, alongside the high quality of alternative data sources, resulted in a score of 0.99, leading to the quality rating of ‘very high’.
Data sources and imputation for Māori descent in the 2023 Census provides more detail and explanation about how data sources were prioritised.
Data sources and coverage rating calculation for Māori descent electoral data, census usually resident population count, 2023 Census | |||
---|---|---|---|
Source for Māori descent electoral data | Rating | Percent | Score contribution |
2023 Census | 1.00 | 82.96 | 0.83 |
2018 Census | 0.99 | 7.55 | 0.07 |
2013 Census | 0.97 | 2.99 | 0.03 |
Admin data | 0.97 | 3.97 | 0.04 |
Parental data | 0.91 | 0.22 | <0.01 |
Deterministic derivation | 0.90 | 0.10 | <0.01 |
CANCEIS(1) nearest neighbour imputation | 0.80 | 2.21 | 0.02 |
No information | 0.00 | 0.00 | 0.00 |
Total | 100.00 | 0.99 | |
1. CANCEIS = imputation based on CANadian Census Edit and Imputation System. Note: Due to rounding, individual figures may not always sum to the stated total(s) or score contributions. |
Consistency and coherence: Very high quality
Māori descent electoral data is highly consistent with expectations across all consistency checks.
The data source methodology for 2023 Census has extended the 2018 methodology to improve the quality of the data and more accurately reflect the real world.
Accuracy of responses: Very high quality
Māori descent electoral data has no data quality issues that have an observable effect on the data. The quality of coding is very high. Any issues with the variable appear in a very low number of cases (typically less than a hundred).
The type of form a respondent used (paper or online, English or bilingual) did not influence their response to the question. Improvement in scanning repair for paper forms reduced the number of responses needing to be sourced from alternative sources.
This data is used to determine the number of Māori electorates in the 2026 General Election. The overall quality of the data is very high and is fit for electoral purposes.
Note: the census data may not correspond with the Māori electoral roll, which is dependent on whether individuals wish to enroll as Māori voters and is restricted to those aged 18 years or older.
To assess how this concept aligns with the variables from the previous census, use the links below:
A Māori descent electoral information by variable was not published in 2013.
Contact our Information centre for further information about using this concept.