Category Scheme V10

Overview

A Category Scheme is a container for Categories. An example of a category scheme is one which categorises data - sometimes known as a subject matter domain scheme or a data category scheme. The individual Categories can be associated to any set of identifiable Artifacts, known as a Categorisation.

Structure Properties

Structure Type	Standard SDMX Structural Metadata Artefact
Maintainable	Yes
Identifiable	Yes
Item Scheme	Yes
SDMX Information Model Versions	2.0, 2.1
URN - CategoryScheme namespace	urn:sdmx:org.sdmx.infomodel.categorycheme.CategoryScheme
URN - categorisation namespace	urn:sdmx:org.sdmx.infomodel.categorycheme.Categorisation

Context within the SDMX 2.1 Information Model

The schematic illustrates the core artifacts of the SDMX 2.1 Information Model, and how Category Schemes, Categories and Categorisations fit in.

Usage

Categories are used within a Category Scheme and has the facility to have one or more child codes as well as being multi-lingual.

The SDMX Cross Domain Concept Scheme provides a range of standardised Concepts maintained by the SDMX Statistical Working Group (SWG) and can be viewed on the Global Registry site https://registry.sdmx.org/items/conceptscheme.html.

More information on Category schemes can be found in this article.

Conventions

Category Scheme IDs IDs are conventionally uppercase using underscores '_' as separators if required. Examples:

Agency	Category Scheme ID ID	Description	SDMX-ML
ESTAT	ESA2010TP	ESA 2010 - Transmission programme	[ https://registry.sdmx.org/ws/public/sdmxapi/rest/categoryscheme/ESTAT/ESA2010TP/1.0 SDMX-ML]
SDMX	STAT_SUBJECT_MATTER	SDMX Statistical Subject-Matter Domains	[ https://registry.sdmx.org/ws/public/sdmxapi/rest/categoryscheme/SDMX/STAT_SUBJECT_MATTER/1.0 SDMX-ML]

Flat Category Schemes

Flat Category Schemes are simple lists of codes with no explicit or implied relationships or hierarchies.

Example Category Scheme

Code ID	Code Name	Description
PUBLIC	Public Sector	Artifacts relating to the Public Sector.
PRIVATE	Private Sector	Artifacts relating to the Private Sector

Category Schemes with Simple Hierarchies

SDMX allows simple hierarchies to be defined within flat Concept Schemes by making a code the parent of codes that logically sit under it in the hierarchy.

Example: SDMX STAT_SUBJECT_MATTER

Code ID	Code Name	Parent
DEMO_SOCIAL_STAT	Demographic and social statistics	(none)
POP_MIGRATION	Population and migration	DEMO_SOCIAL_STAT
LABOUR	Labour	DEMO_SOCIAL_STAT
EDUCATION	Education	DEMO_SOCIAL_STAT

A Category can only have one parent meaning that it can only appear once in a simple Category Scheme hierarchy.