This page explains the types of reviews we undertake for all statistical classifications, and our review process for classifications and statistical standards, including when, why, and how we review them.
Our method of reviewing classifications is an agreed approach between the Standards, Classifications Section of the Australian Bureau of Statistics, and the Classifications and Standards Section of Statistics NZ.
The three types of review for our statistical classifications
Every standard classification is reviewed at appropriate intervals to make sure it is still relevant and meeting the needs of key users. Three types of reviews can be undertaken for a statistical classification:
An update is deemed to be an immediate change, a minor review is scheduled maintenance usually on a four- to five-year cycle, and a major review is scheduled maintenance or development on a 10-year cycle.
A classification update occurs for operational reasons ie an immediate response to reflect needs in administrative collections or because of legislative change.
A classification update does not alter the conceptual base of a classification and should only have very minimal impact on the classification structure (particularly if a hierarchical classification).
A classification update only applies to two New Zealand Standard Classifications. These are:
- New Zealand Standards Classification of Countries (NZSCC) – to reflect immediate need for Customs/Immigration purposes
- New Zealand Harmonised System Classification (NZHSC) – to reflect immediate need for Customs tariff changes announced by the government. The five-yearly changes to the NZHSC statistical keys and structure are considered a minor review.
Classification minor review
A classification minor review occurs on a regular schedule as agreed with stakeholders and/or between the statistical agencies, and as work programmes and resources allow. The scope of a classification minor review may include some or all of the following:
- clarifying category definitions including adding or deleting within categories at the lowest level of a classification of primary activities, alternative titles, or specialisations
- adding emerging and/or new categories at the lowest level of a classification to reflect real world change or, for example, to split categories such as not elsewhere classified.
A classification minor review will usually occur on a four- to five-yearly cycle after a major review unless a shorter timeframe is required, and usually will occur between population censuses. A classification minor review does not alter the conceptual base of a classification, may change the classification structure at the lowest level (of an hierarchical classification), but does not change higher levels of a classification.
Classification major review
A classification major review occurs on a regular schedule as agreed with stakeholders, users, or between the statistical agencies, and as the work programmes and resources allow, or if there is a significant change in an international classification which affects an existing statistical classification used in New Zealand.
A classification major review may include some or all of the following:
- conceptual changes
- structural changes
- definitional changes, including clarifying category scope and revising any inclusions or exclusions.
A classification major review will occur in a 10- to 15-year cycle subject to stakeholder requirements, real-world change, and/or a review strategy agreed on with the Australian Bureau of Statistics.
Our review process for classifications and statistical standards
Classifications and standards are reviewed at regular intervals to ensure they remain relevant and meet the needs of key users. The three key phases of a review are planning, execution, and implementation.
Phase 1: Planning
The first phase begins when the need for a review is identified. We review a classification or standard:
- to reflect changes in society, the economy and the environment
- to align with similar reviews by international agencies
- due to changes in relevant legislation.
Once we have identified the review as a priority, a project team is established and they prepare project management documentation.
The team identifies internal and external stakeholders. Internal stakeholders include those that use the classification and standard in their statistical outputs as well as other experts on the topic concerned. External stakeholders may include central and local government and other key community groups that have a strong interest in the topic.
Key internal stakeholders approve the project plan before the review proceeds to the execution phase.
Phase 2: Execution
In the execution phase, the project team undertake research to assess the current state of the classification and standard, the issues involved, historical practice within Statistics NZ and the wider Official Statistics System, and international practice.
International practice covers relevant work by the United Nations, other international agencies such as the International Labour Organisation, International Organization for Standardization, World Health Organisation, Organisation for Economic and Cultural Development, or other national statistical agencies such as the Australian Bureau of Statistics, Statistics Canada, and the Office of National Statistics.
The research phase identifies:
- the scope of the classification and standard
- the purpose the classification and standard will serve
- the underlying concepts in the classification and standard
- the structural requirements of the classification and standard
- how to meet best practice guidelines, eg mutual exclusivity (a response to a question based on the classification will only fall into one of the categories)
- coding requirements and other practical considerations
- time-series concordances – ensuring that the new classification can be mapped to the old one, so data can be compared over time.
Once the research phase nears completion and the project team have drafted a new version of the classification and standard, we consult stakeholders. Consultation can take a variety of forms, and may include targeted email consultation, face-to-face consultation, or working groups. Consultation gives users of the classification and other experts with the opportunity to provide feedback on the proposed revisions.
The consultation process gives stakeholders more than one opportunity to comment, which helps to ensure that the project team fully addresses stakeholders' needs. The reviewed classification and standard is developed to be fit for purpose and comparable with international standards.
After the review team and stakeholders are satisfied with the reviewed classification and standard, both the classification and standard are submitted to an internal approval process, endorsed by a Statistics NZ management board, and approved by the Government Statistician.
Phase 3: Implementation
Once approved, the classification and standard are published to the Statistics NZ website for public access, incorporated into statistical outputs, and promoted across the Official Statistics System.