METIS 2013 Work Session May 6, 2013

1. Neuchâtel Terminology Model:Classification database object types and their attributesRevision 2013 Prepared by Debra Mair, Tim Dunstan and Alice Born, Statistics Canada and Anne Gro Hustoft, Statistics Norway, And the Working Group on Revision to the Neuchâtel Terminology Model METIS 2013 Work Session May 6, 2013

2. Background: The Neuchâtel terminology model: Classifications (version 2.1) • Developed by the Neuchâtel group - Denmark, Sweden, Norway, Switzerland, the Netherlands and run Software Werkstatt • Objective: to clarify some basic concepts and to arrive at a common terminology for statistical classifications • Defines the key concepts relevant to structuring classification metadata and provides the conceptual framework for the development of a classification database • Lists and describes the typical object types of a classification database, and the attributes connected with each object type • Version 2.1 published in 2004

3. Classification object types and attributes Attributes: Code Official title Alternative titles Explanatory notes General note Includes Includes also Excludes Level number Generated Currently valid Valid from Past events Future events Changes from previous version Updates Classification version/variant Parent item Sub-items Linked items Case laws Index entries Footnotes • Classification family • Classification • Classification version • Classification variant • Classification index • Correspondence table • Classification level • Classification item • Item change • Case law • Classification index entry

4. Why revise now? • Many countries have at least partially implemented the model and have expressed desire for revisions • Need for revision was discussed at 2011 METIS Workshop • METIS Steering Group contacted the UN Expert Group on International Statistical Classifications to work on the revision • Result: a joint working group • Generic Statistical Information Model (GSIM) drew heavily from the Neuchâtel Terminology Model – Concepts Group • revealed the need to clarify and more completely explain certain parts of the Neuchâtel Model

5. Steps in revision process to date • Working group membership: Australia, Austria, Canada, France, New Zealand, Norway, Portugal, Sweden, the United States, Eurostat, ILO, UNECE, and UNSD • Questionnaire sent out to 25 countries and international organizations, members of the revision group plus others implementing the Neuchâtel Terminology Model • 18 responses received • Results showed interest in revisions, revealed key areas for revision and provided suggestions for potential revisions • The proposals received and others developed by working group members are currently under consideration by the working group

6. Type of revisions under consideration • Definition changes • Object deletions • Attribute deletions, additions • Clarifications, additional examples • Database restructuring • Mapping to GSIM

7. Neuchâtel terminology model Classification Family Potential removal or “demotion” to attribute 1 Classifications * Classification Object to be modified 1 1 * * source_version 1 * Correspondence Table Classification Version Classification Variant * target_version 1 1 1 1 * * Classification Level Classification Index 1 1 sub_items * * * 1 * * source_items 1 Correspondence Item Classification Item Classification Index Entry 1 * * target_items 1 * * past_events future_events * * Case law Item Change

8. Definition changes: classification version From current definition of classification version: • A new version of a classification differs in essential ways from the previous version. Essential changes are changes that alter the borders between categories, i.e. a statistical object/unit may belong to different categories in the new and old version. Border changes may be caused by creating or deleting categories, or moving part of a category to another. The addition of case law, changes in explanatory notes or in the titles do not lead to a new version. Feedback • Clarification to the types of changes that could occur without requiring recognition of a new version and the minimum change required for a new version.

9. Definition changes: classification variant A variant is currently defined as having two characteristics: • At least one level of the variant is also present in its base classification version. • The variant and base classification version are based on similar grouping criteria. • Feedback • definition is too restrictive • fails to acknowledge the relationship to the base version of a classification built from its classification items (categories), but introducing a new grouping criterion (e.g., ICT variant of ISIC) • does not recognize as variant classifications built from different levels of the base version.

10. Criteria considered for distinguishing between classification versions and classification variants • Registration status • Has the previous version been superseded by the introduction of the new classification? • Purpose • Does the new classification serve the same purpose or does it serve some special purpose? • Structural changes • What is the nature of the structural changes made to the first classification in order to create the second?

11. Proposed revised definition for:Classification Version • A classification version is a list of mutually exclusive categories representing the version-specific values of the classification variable. If the version is hierarchical, each level in the hierarchy is a set of mutually exclusive categories. A classification version has a certain normative status and is valid from a particular date for a period that may or may not be specified.A new version is created when a classification version is superseded by the introduction of a new classification version that differs in essential ways from the previous version. Essential changes are changes that alter the borders between categories, i.e. a statistical object/unit may belong to different categories in the new and old versions. Border changes may be caused by creating or deleting categories, or moving part of a category to another. These changes can occur at any level of the classification. The addition of case law, changes in explanatory notes or in the titles do not lead to a new version. • It should be noted that if a classification is superseded by a new version, the two versions will likely serve the same objective or purpose. • Floating classifications are considered to constitute one version.

12. Proposed revised definition for:Classification variant • A variant is built from the classification items of a base classification version. These classification items need not all be found at the same level in the base classification version. To these classification items, one or more new levels may be added. This can include extending the base classification version with one or several new levels at the bottom of the base classification version, creating a new lowest level.   • It should be noted that variants are typically developed to serve a specific purpose. • Removed from definition: variant and base classification version are based on similar grouping criteria

13. Database re-structuring - example Classification Index (attribute: index entries) • Index entry appears three times in the • database structure - classification item, • classification index and classification • entry item Classification Index Entry (list of all entries) Classification Item (attribute: index entries) • proposal: index entries be dropped from classification item and classification index • Classification item and classification index be added as attributes to classification index entry • identify classification versions and variants to which the index entry • is associated

14. Mapping Neuchâtel and GSIM GSIM Conceptual model • 10 out of 17 objects • map 1 to 1 between • Neuchâtel and GSIM • Neuchâtel has more • detail • Some conceptual • differences Neuchâtel Terminology Model SDMX DDI Implementation standards Other relevant standards Geospatial standards

15. Neuchâtel terminology model – object graph Classification Family Inheritence 1 * 1:N relationship 1 Classifications * Classification 1 1 * * source_version 1 * Correspondence Table Classification Version Classification Variant * target_version 1 1 1 1 * * Classification Level Classification Index 1 1 sub_items * * * 1 * * source_items 1 Correspondence Item Classification Item Classification Index Entry 1 * * target_items 1 * * past_events future_events * * Item Change

16. Generic Statistical Information Model (GSIM) – object map Classification Classification Family groups groups Classification Scheme has has has contains Classification Version Classification Variant Level groups groups maps Correspondence Table Map Classification Item contains maps

17. Next steps • Reach agreement on set of proposed changes by the WG, METIS and EG on classifications • Working group finalizes the revisions by the end of the year, and determines the appropriate way to publish the revised model • Address remaining issues on mapping to GSIM (and other standards) and stewardship of the model

19. Questions for discussion • A key question for this project is the potential relationship between Neuchâtel mode and GSIM • Should this project aim to produce a new version of the Neuchâtel Model for Classifications or might an expanded GSIM take in the information objects of Neuchâtel? • Based on the decisions from point one, is there a need to address the issue of governance and stewardship of the Neuchâtel model. Currently, there is no formal owner of the model, and this is the first attempt to revise it. • While members of the working group supported “joint” stewardship between UNECE METIS – UN EG on classifications, will this be feasible?