Simple Dublin Core:
Dublin Core (dc) is a metadata standard commonly used in repositories for harvesting. It is based on a central set of 15 metadata fields (external link). This set is known as 'simple' or 'unqualified' dc. Qualified dc expands upon the basic 15 fields.
Unqualified dc is used as the core metadata standard for repositories and harvesters that use the OAI-PMH protocol to be able to harvest metadata from a repository.
However, simple dc is limited. When the Scholarly Works Application Profile was being developed, work was undertaken on examining these limitations. Please click here to link to this work. Some of the fields available are so broadly defined that they are unlikely to be used uniform ally.
For example, there is just one simple field for 'date' even though several different types of date are likely to be associated with a repository object. If all dates are harvested from a repository as a simple dc:date, useful qualifying information about the type of date will be lost.
Mapping a full set of metadata about an object to a simple dc record is
not straightforward. However, VIF has identified which fields can be
used by repository managers to map
essential version information to in order to
allow the harvested record to retain enough information to make an
assessment of the version status of an object. However, it should be
noted that simple Dublin Core is insufficient to be used as a basis for
what metadata to keep in a repository. It is only used to export
metadata in s fixed and shared format.
DC and the VIF Essential Version Metadata:
Simple Dublin Core fields are a starting point for storing version metadata, but are not adequate to describe in any detail, or to establish version relationships. Qualified Dublin core is able to give a far more complete account of version status and relationships.
-
Defined Dates:
dc:date Additional dates associated with the object should be stored by the repository, but only one date can be exported using the date field without causing confusion. Therefore for exporting with OAI-PMH, VIF recommends that the date used exported:
Publication Date / Date Available (do not use date deposited - see dates section)
-
Identifiers:
dc:identifier Full URL http://www.examplerepository.com/record1234 dc:identifier Other identifier Repository Number - Version Numbering:
Simple dc does not provide a suitable field for storing version numbers. However, the description field could be used for this purpose.
- Version Labels or Taxonomies:
Version labels could also be stored in description, please see below:
- Text Description:
dc:description If at all possible use this field for a statement about version status For example: This is the author's final version. A published version which has been proof read and formatted is available on the publishers website
Additional Field Usage:
Further information that may help identify a version can be
stored in the dc:realtion field. This is easier in simple Dublin Core as the example entries speak for themselves without the need for qualification:
| Simple dc field: | Notes: | Example entry: |
| dc:relation | URL of summary/splash page | http://www.examplerepository.com/splash123 |
| dc:relation | Publisher webpage | http://www.publisher.com |
| dc:relation | Author's own webpage: | http://www.instituiton.ac.uk/authorsownpage |
| dc:format | For electronic resources this will usually correspond to a MIME type | application/msword |
Dublin Core Mapping:
Mapping of metadata to Dublin Core fields is not however going to be uniform across repositories, as different repositories store different pieces of metadata in different ways. Individual software packages also allow you to ascribe metadata at different levels.
The limitations of simple Dublin Core have led to the development of metadata structures that are more able to describe objects in more detail, such as Qualified Dublin Core and Dublin Core application profiles.
Next:
Read about how
Qualified Dublin Core can store more
complex version information.