Concept Scheme V10

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Overview

A concept scheme is a container for Concepts which are reusable definitions for statistical items such as frequency, currency, and reference area (country).

Concepts may be referenced by multiple structures in SDMX, and therefore provide re-usable mechanism for giving meaning to structures.

A Data Structure Definition (DSD) provides a good example of how Concepts are used as to create a DSD. When defining a Data Structure Definition, each Dimension, Attribute and Measure is given a specific Concept. The dimensions etc. do not have names or descriptions, instead they provide a reference to a Concept which gives this information. To get a human readable name for a Dimension, the referenced Concept must first be obtained.

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 - ConceptScheme namespace urn:sdmx:org.sdmx.infomodel.conceptscheme.ConceptScheme
URN - concept namespace urn:sdmx:org.sdmx.infomodel.conceptscheme.Concept

Context within the SDMX 2.1 Information Model

Concept Scheme

Usage

Concepts are used by Dimensions, Attributes, Measures, and Metadata Attributes to provide them with a semantic meaning. Concepts can also be used to define a default representation, for example it is possible to link the Concept of Frequency to a Codelist containing all the Frequency Codes, and any structure using the Concept will inherit the default representation.

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.

Conventions

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

Agency Concept Scheme ID Description SDMX-ML
ESTAT CS_NA ESA 2010 - Transmission programme SDMX-ML
SDMX CROSS_DOMAIN_CONCEPTS SDMX Cross Domain Concept Scheme [1]

You can seem more examples and information on Identities in this article.

Flat Concept Schemes

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

Example: SDMX Cross Domain Concept Scheme

Code ID Code Name Description
ACC_CONV Accounting conventions Practical procedures, standards and other aspects used when compiling data from diverse so...
ACCURACY Accuracy Closeness of computations or estimates to the unknown exact or true values that the statistics w...
ACTION_TYPE Action type Behaviour to be undertaken by a system processing the information contained in a SDMX mess...
AGE Age Length of time that an entity has lived or existed.
CIVIL_STATUS Civil status Legal, conjugal status of each individual in relation to the marriage laws or customs of the countr...

Concept 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.

Imagine a Concept Scheme including a Concept 'CONTACT' containing individual codes for details such as Name, Address, and Email etc. A simple hierarchy for CONTACT can be created by setting CONTACT as the parent for each of the Contact detail codes:

Code ID Code Name Parent
CONTACT Contact (none)
CONTACT_NAME Contact name CONTACT
CONTACT_EMAIL Contact email address CONTACT
CONTACT_ORGANISATION Contact organisation CONTACT
CONTACT_PHONE Contact phone number CONTACT
CONTACT_MAIL Contact mail address CONTACT

Other than acting as a parent, CONTACT behaves as a normal code allowing series for CONTACT or any of the individual details.

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