Metadata
This page explains the description template used in the COCOON catalogue for warehouse resources.
Metadata is information about other information. They are also called descriptors. In conventional libraries, documents are described by means of bibliographic records which identify authors, publishers, titles, dates of publication, etc. The bibliographic records are used to describe the documents. These records are useful both to librarians in managing their holdings and to users in finding a document.
For a digital document, and more particularly in the case of Internet distribution, these records are known as "metadata" and the documents as "resources".
Electronic documents are becoming more and more important in our daily lives and their number has only increased over time. Searching for a document in the mass of existing documents has become both a complex and indispensable task, especially since this search is now carried out in distributed architectures. It is in this context that the concerns of standardisation of coding and metadata exchange practices have their origins.
Metadata in COCOON
COCOON uses the OLAC model to describe the resources in its catalogue. This OLAC model is an extension of the qualified Dublin-Core model, itself based on the simple Dublin-Core model. (See explanations below).
Simple Dublin-Core
In 1995, in Dublin, Ohio, representatives of diverse communities from the library, computing and web worlds met to define a common core of metadata: the Dublin Core Metadata Initiative (DCMI), often abbreviated to 'Dublin-Core'.
The Dublin-Core is a set of 15 descriptors with a very broad scope and a very generic meaning. Some relate to content, others to intellectual property, and others to instantiation. This set of descriptors was standardised within the ISO in 2003 under the name "ISO Standard 15836-2003. The 15 descriptors are: Contributor, Coverage, Creator, Date, Description, Format, Identifier, Language, Publisher, Relation, Rights, Source, Subject, Title, Type.
Qualified Dublin-Core
The basic elements of the simple Dublin-core may in some cases not be sufficiently precise, in which case it is possible to use another set of "qualifiers" that clarify the meaning. Dublin-Core defines two classes of qualifiers:
- "Refinements" which make the meaning of an element more specific. For example: instead of the element date it is possible to use one of the following refinements: created, valid, available, issued, modified, dateAccepted, dateCopyrighted, dateSubmitted;
- Encoding schemes, and controlled vocabularies such as the "Point" scheme which allows to define the properties of a geographical point (coordinates: longitude, lattitude, altitude, projection used, name).
Open Language Archive Community
OLAC is an international organisation bringing together a number of institutions and individuals concerned with the sharing and dissemination of linguistic resources. The aim of OLAC is to organise this community so that documents can be easily exchanged. For this purpose, OLAC has made two strategic choices since its foundation in 2000: the qualified Dublin-Core, to which it has added 5 attributes linked to controlled vocabularies to clarify its meaning and adapt it to the community's practice, and the OAI for the dissemination of this metadata. The additions to Dublin-Core are the following:
- A language attribute can be added to the subject and language elements. Its value must be one of the 3-character identifiers of the ISO 639-3 standard.
- A language-field attribute may be added to the subject element. It must take its value from a closed list (phonetics, phonology, pragmatics, psycholinguistics, ...).
- A discours-type attribute can be added to the type and subject elements. (closed list)
- A linguistic-type attribute can be added to the type element. (closed list)
- A role attribute can be added to the contributor and creator elements. It must take its value in a closed list (recorder, researcher, signer, singer, speaker, transcriber, translator, ...).
To organize the community, OLAC assumes the role (in the OAI sense) of aggregator as well as service provider. OLAC maintains a list of resource providers (including Coccon) which it regularly collects, evaluates the quality of their descriptions (statistics ) and offers a search engine (OLAC Language Resource Catalog ).