Concept

Unit of thought created by a unique combination of characteristics.

At an abstract level, a Concept is defined in the Generic Statistical Information Model (GSIM) as a "unit of thought differentiated by characteristics". Concepts are used in different ways throughout the statistical lifecycle, and each role of a Concept is described using different information objects (which are subtypes of Concept). A Concept can be used in these situations: (a) As a characteristic. The Concept is used by a Variable to describe the particular characteristic that is to be measured about a Population. For example, to measure the Concept of gender in a population of adults in the Netherlands, the Variable combines this Concept with the Unit Type "person". (b) As a Unit Type or a Population. To describe the set of objects that information is to be obtained about in a statistical survey. For example, the Population of adults in Netherlands based on the Unit Type of persons. (c) As a Category to further define details about a Concept. For example, Male and Female for the Concept of Gender. Codes can be linked to a Category via a Node (i.e., a Code Item or Classification Item), for use within a Code List or Statistical Classification. In SDMX the concept can be given a Core Representation such as a reference to a code list for an enumerated representation or other values such as "integer" or "string" for a non-enumerated representation. This representation can be overridden in the data structure when the concept is used as a dimension or attribute. A concept with a core representation could be regarded as a represented variable.

urn:sdmx:org.sdmx.infomodel.conceptscheme.Concept=SDMX:CROSS_DOMAIN_CONCEPTS(2.0).CONCEPT