StructuralMetadata English (en)

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Introduction

Structural Metadata are the metadata acting as identifiers and descriptors of the data. They must also be associated with the dtaa they refer to in order to enbale their identification, retrieval and better understanding.

Structural metadata can be for instance the name of a statistical table, of a statistical variable or the dimension of a statistcial cube.


Structural metadata are generally represented with full text strings or with codes. In the following page, we will focus on the harmonisation of the lists of codes (code lists) used for the exchange of data and metadata in SDMX.


The use of harmonised (common) code lists is crucial in the processes of collection, exchange and dissemination of data in order to facilitate their understanding and comparability.

The process of harmonisation of code lists is currently made at two levels: at Eurostat level and at SDMX levels.

These both processes are working in parallel with an objective of synergy so that no discrepancy appears between the code lists and codes used at both levels.



The Eurostat standard code lists (SCL)

In Eurostat, the project of harmonisation has started few years ago.

The objective is to reduce the number of code lists used in Eurostat dissemination (more than 500 code lists) and that each statistical concept is represented by one and only one code list.


The Eurostat Standard Code LIsts (SCLs) are defined on the basis of official classifications and their creation follow a certain number of basic 'rules', like:

  • Codes made of less than 12 digits
  • Alphanumerical codes starting with a letter (avoiding 'leading zeroes')
  • Some special characters allowed ( the dash '-' for intervals and the undersocre '_' for sums)

 

Those SCLs are then used for the Eurostat data dissemination and highly recommended when implementing SMDX in a statistical domain.


The exhaustive list of Eurostat SCLs is publicly disseminated on RAMON and is available here: Eurostat Standard Code Lists



The SDMX cross-domain code lists

 

In its Annex 2 of 2009, the SDMX Content-Oriented Guidelines released 9 "cross-domain code lists".

These code lists cover relatively general statistical concepts which are often retrieved in several statistical domains.


SDMX recommends to use these code lists when their appropriate concepts are used for data collection and exchange between statistical organisations.


The maintenance of these code lists is manages by the SDMX Statistical Working Group (SWG).

This group has been created in 2011 with the objective of maintaining and revising the SDMX statistical standards.

A series of additional code lists are now proposed to the SWG by the different SDMX organisation (including Eurostat) who will evaluate them with the aim of extending the list of SDMX cross-domain code lists. 

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