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Iwi statistical standard: Draft April 2017

Introducing the draft iwi statistical standard

Iwi statistical standard: Draft April 2017 offers a chance to provide feedback on updates to the Iwi statistical standard.

See Iwi statistical standard: 2017 review consultation to give feedback.

This standard provides guidelines for how to gather, organise, and report iwi and iwi-related groups’ information and statistics. This standard is useful to those who collect iwi information, including iwi, Māori, government agencies, and researchers.

This document provides detailed and technical information for people using and implementing the standard.

See Summary of the draft iwi statistical standard for a less technical commentary.

Tātai whetū ki te rangi mau tonu, tātai tāngata ki te whenua ngaro noa.

This whakatauki states that while people come and go, the stars in the heavens will always be there. It reminds us that statistics and data remain, even after those they relate to depart.


Whakapapa is central to Māori identity

The concept of whakapapa is central to Māori identity and understanding Māori worldviews. Whakapapa tells a story of where a person comes from, their surroundings, and their relationships with others. Whakapapa connects Māori to their tipuna (ancestors), to the natural environment (eg mountains, waters, or tribal lands), and to each other. It binds the kinship groupings of iwi, hapū, and whānau together. In contemporary settings, these groupings have significance independently and together. Ties to these groupings are different for different people and may develop and change over time or in different situations.

Iwi is part of Māori identity

For many people of Māori descent iwi is only one part of their Māori identity. Because of this, it is beneficial for people using and applying this standard to understand iwi within the wider context of Māori identity.

An iwi is one of the largest kinship groupings and is generally made up of several hapū that are all descended from a common ancestor. Hapū are clusters of whānau (families) where the whānau is usually an extended family grouping made up of children, parents, often grandparents, and other closely related kin.

Changes over time

The concept and definition of iwi are fluid and dynamic. These changes create challenges with defining and classifying iwi for statistical purposes. Discussions about what represents an iwi and which groups and names should be included in iwi lists are ongoing. For these reasons, existing lists of iwi will differ, based on the concept and definition used. This means the groups in Stats NZ’s iwi classification (list) may or may not be listed as an iwi elsewhere.

See below for the standard’s definitions of concept and iwi.

Other concepts commonly collected with iwi information

The concepts of Māori descent and ethnicity are often collected together with iwi. ‘Descent’ refers to biological ancestry and ‘ethnicity’ to cultural affiliation.

Māori descent

Māori descent is a biological concept.

There is an important relationship between Māori descent and iwi. Only people who have Māori descent should report their iwi, but this is not always the case. Some people prefer not to acknowledge Māori descent but instead identify only with specific iwi or hapū (Robson and Reid, 2001). Some people also prefer not to provide this information to the Crown.


Ethnicity reflects the ethnic group(s) that people identify with or feel they belong. Ethnicity is a measure of cultural affiliation, as opposed to race, ancestry, nationality, or citizenship (Stats NZ, 2005).

History of the iwi statistical standard

The current classification of iwi was first developed in 1991, followed by the statistical standard in 1994. Minor updates to the iwi classification have generally taken place before each Census of Population and Dwellings but it was not until 2016 that the standard was first reviewed in its entirety (Stats NZ, 2016a).

As part of the 2016 review of the standard for iwi, Stats NZ carried out research and consultation. This involved public submissions and discussion, including hui with iwi and Māori; a review of the academic literature on Māori groupings; and interviews with representatives from key government agencies (Stats NZ, 2016b).

Some key recommendations from this research and consultation were to:

  • highlight that the standard is for statistical purposes (Recommendation 1) 
  • update the iwi standard and classification (Recommendation 2) 
  • change the process for including groups in the classification (Recommendation 3).

See Recommendations from the 2016 review of the statistical standard for iwi (Stats NZ, 2016c) for more information.

We updated the Iwi statistical standard to reflect changes required from the review.

Purpose of the iwi statistical standard

As a Treaty of Waitangi partner and New Zealand’s national statistics office, Stats NZ plays an important role in ensuring meaningful information about and for Māori is available. The purpose of this standard is to provide guidelines for gathering and reporting iwi and iwi-related information, so it is valuable and useful to iwi, Māori, and government.

This standard aims to enable collecting data:

  • to provide iwi, iwi-related groups, and Māori with the information they need to support the well-being and development of their people 
  • to provide government with information about iwi and iwi-related groups to support making policy and decisions 
  • that can be compared across surveys and collections.


An iwi, or Māori tribe, is one of the largest kinship groupings and is generally made up of several hapū that are all descended from a common ancestor. Hapū are clusters of whānau where the whānau is usually an extended family grouping consisting of children, parents, often grandparents, and other closely related kin.

Definition of iwi

For statistical purposes, an iwi is defined as a whakapapa-based kinship grouping that generally has several hapū and one or more active marae, and a recognised structure that represents the interests of the iwi, such as a rōpū whakahaere, committee, or board.

Note: Different definitions of iwi are used in different contexts. The definition above is used for gathering and reporting iwi and iwi-related information and statistics.

Scope of this standard

The iwi standard is designed for statistical purposes and is also available for general use. This standard can be used in survey, administrative, and other data collections.

The focus of the iwi standard is whakapapa-based kinship groupings.

Iwi standard classification

Classification scope

An inclusive approach is used to include iwi and other iwi-related groups (whakapapa-based kinship groupings) in the iwi classification.

The iwi classification aims to:

  • capture the dynamic and changing nature of iwi and iwi-related groups 
  • provide a standard approach for grouping and reporting iwi and iwi-related groups.

Conditions for inclusion

To be included in the iwi classification, groups must be whakapapa-based kinship groupings. Groups should be existing hapū becoming iwi, a collection of hapū, or an iwi-related group.

Groups listed as an iwi, in recognised iwi lists such as Te Kāhui Māngai, Tūhono, or the Māori Fisheries Act 2004, will be included in the iwi classification. In the future, iwi listed in other national and local government agencies’ iwi lists may also be included. These iwi lists will need to be whakapapa-based kinship groupings, and will have undergone an appropriate process for determining which groups to include.

Kinship groups that are not listed as an iwi in recognised iwi lists are encouraged to provide information for the group to consider them for inclusion.

This includes information about whether a group has:

  • a shared Māori descent line and its own traditions 
  • one or more active marae – these do not need to be physical buildings
  • a recognised structure that represents the interests of the iwi, such as a rōpū whakahaere, committee, or board.

In collaboration with other government agencies and in partnership with Māori, Stats NZ will consider the information a group provides for inclusion.

Note: Population size is not used to decide whether to include a group in the classification. Small groups can be included, but detailed information about them should only be released if confidentiality and privacy conditions are met.

See Confidentiality and privacy section below.

Note: Including a group in the iwi classification does not mean the group is recognised as an iwi in every context – such as in legislation, in other recognised iwi lists, or by other Māori authorities.

Description of iwi standard classification

The iwi standard classification has two levels and is made up of iwi and iwi-related groups that meet the concept and definition in this standard.

The first level is a statistical region; the second level lists the iwi and iwi-related groups.

This classification has five extra categories for placing responses that:

  • cannot be identified 
  • are not related to iwi 
  • are ‘no response’, when someone identifies they have Māori descent but does not provide an iwi or iwi-related group 
  • are don’t know 
  • are a refusal to answer the question in interviewer or administrative collections.

Classification updates

The classification will be updated annually or when there is a need. For instance, it may need updating in response to a query from an iwi, Māori authority, government agency, or before a specific collection or survey.

Contact if your group is missing from the iwi classification. These groups will be invited to complete a form, which asks for information based on the conditions for inclusion.

We will indicate changes to the classification by updating the version number when the classification is ready to be used.

See classifications and standards under review for the latest news about any changes.

Collecting iwi information

This section provides requirements and guidelines for collecting iwi information. Following this guidance improves data quality and the experience of people answering a question on iwi. It also ensures that iwi information is comparable.

Requirements for collecting iwi information


Collecting information on a person’s iwi is through self-identification. Sometimes a person may be unable to answer a question on their iwi by themselves (eg for children or through death, injury, or sickness). In these cases, a parent, child who is an adult, spouse, partner, or other next-of-kin can answer.

Note: Collecting iwi information through self-identification is different from an iwi register, which usually asks for proof of whakapapa to confirm if a person belongs to an iwi.

Allow for multiple responses

Some people belong to more than one iwi. Where possible, give people the option to provide a minimum of three responses to an iwi question.

It is not appropriate to ask for ‘main’ or ‘most important’ iwi.

Collect information on iwi region (rohe)

Some iwi names are common to more than one region (rohe). To help place an iwi in the correct category, collect information on the iwi’s location.

Guidelines for collecting iwi information

Type of collection

Collecting iwi information is appropriate for written or electronic self-administered questionnaires, and for interviewer-administered collections.

Electronic questionnaires

When using an online questionnaire to collect iwi and iwi-related groups, embed an ‘as-you-type’ list into the response area. This auto-suggests categories as the person begins typing, and can reduce response burden and speed-up processing.

With an as-you-type list, people must still be able to freely type their iwi, if their iwi is not in the list.

Interview-administered collections

If interviewer-administrated collection of iwi and iwi-related groups is required, it is better through a face-to-face interview rather than by telephone. Due to potential te reo Māori language limitations of an interviewer, phone collections should be used with caution.

Write-in responses

When asking a question on iwi and iwi-related groups, provide people with the option for writing in their response(s). Doing this themselves is in keeping with the self-identification definition. Choosing from a pre-determined list may prevent people indicating all the iwi they belong to.

It is important people have enough room to write in the full length of their iwi name(s).

Māori descent

Māori descent does not need to be collected with iwi.

However, if Māori descent is collected with iwi in an online or paper form, it is important to document any linking (routing) between the questions. This is important, because in some collections Māori descent is used to link (route) people to the iwi question, so those who mark ‘no’ to Māori descent cannot answer the iwi question. This may be done to reduce the burden on people who are unlikely to belong to an iwi.

To avoid undercounting, all valid iwi responses are counted in some collections, even if a person has marked ‘no’ to Māori descent or has not recorded an answer. In general, each collection needs to provide information about the processes they use for comparison and integration.

Tick box option for people who don’t know their iwi

Providing a ‘don’t know the name of my iwi’ tick box will make answering the iwi name easy for people without that information.

Where to place an iwi question

A question asking for iwi and iwi-related group information is best placed with other identity questions on forms or questionnaires.

Help and guidance

Some collections use a reference list of iwi names to help guide people. Providing reference lists can be helpful for some people, but it may also influence what people report.

Note: Any reference list of iwi should include a statement such as “This list is for reference purposes only, and is not a full list of all iwi or iwi-related groups”.

Classifying responses

There are potential difficulties with placing iwi in the correct classification category. Iwi responses can include: differences in spelling; other concepts such as waka, hapū, or geographic markers; different prefixes; or older or traditional iwi names.

Common problems for placing responses

Multiple responses

When asking for iwi names, it is expected and acceptable for a person to provide more than one response – up to three is the minimum recommended for systems with limited space. Collect and classify multiple responses in the order they are reported.

In situations where more responses are collected than can be stored, use a random method for reducing responses.

Waka or iwi confederation

If a person provides a waka or an iwi confederation, classify to the correct 'iwi not named, but waka or iwi confederation known' category in level 1 of the classification.

Iwi name common to more than one region

If a person provides an iwi that is common to more than one region but does not provide the iwi region, classify to the correct 'iwi named but region unspecified' category in level 1 of the classification.

Hapū name common to more than one iwi

If a person provides a hapū that is common to more than one iwi, classify to the 'hapū affiliated to more than one iwi' category in level 2 of the classification.

Other points to consider when classifying responses

Spelling differences

When classifying iwi, it may look as though a person has misspelt their iwi. Take care when classifying these responses. These may be different spellings of the same iwi or they may be the names of different iwi. Some iwi names only differ by one or two letters.

Prefixes differ

Some iwi have different prefixes but look as though they share the same ancestor name. In some cases, the same iwi is being referred to, as the different prefixes are dialectical (eg Kāi and Ngāi). In other cases, the prefixes indicate different iwi (eg Ngāi and Ngāti).

Store responses at response-list level

Where possible, store responses to the iwi question at the response level rather than at the classification (output) level. Doing this allows information to be reported using standard statistical reports and user-defined reports. If it is not possible to store iwi responses in the response-level format, store them at the synonym level (list of likely responses) or at the lowest-level possible.

Stats NZ maintains a response list and a list of synonyms that people can request.

Email if you need this information.

Imputation and substitution

When collecting information on identity (eg iwi), it is best to avoid imputation. Imputation occurs when information is substituted into the place of missing responses.

In some situations where a person does not provide their iwi, it may be appropriate to assign their iwi – using information already held.

Reporting iwi information

This section describes how to report information collected from an iwi question. Two types of lists can be published; – one is the standard classification for statistical reporting; the other is a response list for response-level reporting.

Statistical reporting

When reporting iwi statistics to government, it is important to use the iwi standard classification. Using this allows iwi statistics to be compared across surveys and collections.

Iwi standard classification

Responses to the iwi question that meet the concept and definition of iwi are grouped together in iwi classification categories for reporting.

Iwi are first categorised by the statistical geographic area in the top level of the classification. This is because iwi with the same name are located in different parts of New Zealand. Categorising iwi geographically places them in the correct location.

Hapū responses are grouped with their iwi if location information is provided. Hapū that could go to multiple iwi are classified separately. Waka responses are classified in the iwi classification in separate categories. Responses that cannot be correctly placed in an iwi category are added to the ‘not identifiable’ category.

Response-level reporting

When collecting iwi information, people may provide other Māori identity groupings they belong to, such as traditional marae or urban marae, as well as other concepts, such as maunga. Together with iwi responses, we include these in a response list. This list allows people, including iwi, Māori, researchers, to group and report responses from an iwi question in a way that is useful to them.

Iwi response list

The iwi response list is made up of actual written responses not grouped into classification categories. It can be used to report the majority of responses to a question on iwi.

The iwi response list is made up of responses to the census iwi question that are based on Māori descent. Responses with at least [10] counts are a separate category in the response list. Because we created the response list using the actual written responses from people, categories include both whakapapa-based kinship groupings and non-kinship Māori groupings.

The response list is broader than the iwi standard classification because it is actual responses – some categories from the response list are grouped together in the classification. For instance, hapū responses are separate categories in the response list, but are grouped together with their iwi in the iwi standard classification. As a result, counts may differ for the response list and the classification.

Note: We are preparing a paper on the methods used for producing response-list reports.

Other points to consider when reporting about iwi

Reporting multiple responses

People often provide more than one iwi name. This means the total number of iwi responses is greater than the total number of people reporting their iwi.

Note: If a person provides an iwi, and provides a hapū classified to that same iwi, only one response should be counted. If a person provides an iwi and provides a hapū classified to a different iwi, both responses should be counted.

Time series

Stats NZ will make a concordance (mapping) that links iwi categories between different versions of the classification. This shows where iwi groups have been split, or combined, between the different classification versions.

Time series provide a count of responses over the different years a survey or collection is run. Adding new iwi and iwi-related groups to the iwi classification may affect time-series information.

Time series may change when the classification is updated as some responses will go to a new category or categories. This decreases the counts in the iwi categories they came from.

Back-casting data may be used when a new iwi or iwi-related group is added to the classification and its information from past surveys or collections is available. Responses from these collections are counted for the separate category and are not shown in the former iwi category count. This enables the new group to have its information available from past surveys.

Collecting iwi in long-running surveys

When collecting iwi in surveys that run for several years, allow for changes in how people self-identify their iwi. There may be inconsistencies in different surveys, or at different times, because of the collection context and other factors.

Web-based classification tool

Ariā is a web-based classification tool that is currently being developed. People will be able to access the iwi standard classification and the iwi response list from here. In the future, people will be able to create their own reports in Ariā by choosing the classification or list categories they require.

Access Ariā on the innovation website.

Confidentiality and privacy

Iwi information should only be reported and shared if the counts do not cause a privacy or confidentiality concern by allowing a person to be identified. This means smaller groups can access their counts, but they might not be able to access more-detailed information about their group, such as age, sex, occupation, or areas where people live.

See Privacy, security, and confidentiality of information supplied to Statistics NZ for Stats NZ's guidelines around confidentiality and privacy.


Clusters of whānau (families) where the whānau is usually an extended family grouping consisting of children, parents, often grandparents, and other closely related kin.

iwi-related groups
Kinship groupings with a shared Māori descent line, such as a waka grouping or confederation.

A traditional meeting place for whānau, hapū, and iwi members (Abridged from: Te Kāhui Māngai).

Mountain, mount, peak (Source: Māori dictionary)

non-kinship Māori grouping
Non-kinship Māori groupings connect people of Māori descent, but are not bound by ancestral lineage. Non-kinship Māori groupings are typically locality-based.

urban marae
Non-traditional marae, not specifically associated with any particular hapū. Urban marae often serve as meeting places for the wider community and are also commonly called Community, Ngā Hau e Whā, Ngā Mātā Waka, or Pan-tribal marae (Abridged from: Te Kāhui Māngai).

Ancestor, grandparent, grandfather, grandmother (Source: Māori dictionary).

Allied kinship groups descended from the crew of a canoe that migrated to New Zealand and now occupying a set territory (Source: Māori dictionary).

Genealogy, genealogical table, lineage, descent. Reciting whakapapa was, and is, an important skill and reflects the importance of genealogies in Māori society – for leadership, land and fishing rights, kinship, and status. It is central to all Māori institutions (Abridged from: Māori dictionary).

A family or extended family (Source: Te Kāhui Māngai).


Moorfield, J (nd). Māori dictionary. Retrieved from http://Mā

Robson, B, & Reid, P (2001). Ethnicity matters: Māori perspectives. Retrieved from

Stats NZ (2005). Statistical standard for ethnicity. Retrieved from

Stats NZ (2016a). Review of the statistical standard for iwi: Summary of key points. Retrieved from

Stats NZ (2016b). Discussion of findings from the 2016 review of the statistical standard for iwi. Retrieved from

Stats NZ (2016c). Recommendations from the 2016 review of the statistical standard for iwi. Retrieved from

Te Puni Kōkiri (nd). Te Kāhui Māngai: Directory of iwi and Māori organisations. Retrieved from


See Copyright and terms of use for our copyright, attribution, and liability statements.


Stats NZ (2017). Iwi statistical standard: Draft April 2017. Retrieved from

ISBN 978-0-9941463-4-2 (online)

Published 6 April 2017 

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