A citation Element Refinement for dc:identifier

Dublin Core Metadata Initiative - Citation Working Group

28 March 2002

This version: <http://dublincore.org/usage/meetings/2002/05/citproposal.html>
Previous version: This is the first version for review
Latest version: <http://epub.mimas.ac.uk/DC/citproposal.html>

Author: Ann Apps <ann.apps@man.ac.uk>
MIMAS, University of Manchester, UK

Status of this document: Under Review

Description: This document contains a proposal by the DCMI Citation Working Group [1] to the Dublin Core Usage Board for a citation element refinement for dc:identifier. A dc:identifier element with a citation qualifier would provide a field in which to encode the bibliographic citation information for a journal article, or other bibliographic resource, within the Dublin Core record for that resource.


Element dc:identifier
Proposed Qualifier citation
Source of Proposal DCMI Citation Working Group [1]
Justification See section 4
Overlap with other terms None
Impact There will be existing DC applications which have used differing methods for solving this problem, but there is no existing best practice
Interoperability No expected impact because this is a new, optional element refinement
Examples See section 3

1. Introduction and Objective

This document describes a proposal to the Dublin Core Usage Board to provide a specific field within the Dublin Core metadata for a bibliographic resource, such as but not limited to a journal article, in which to record the bibliographic citation information for that resource. It is proposed that this field be within a dc:identifier element with a citation qualifier.

The primary purpose of recording the citation information for a bibliographic resource is to support discovery of that resource, because it would assist with discovery of the resource's location. In addition, capturing the bibliographic citation information for a resource will support description of this type of resource.

It should be noted that the bibliographic information which would be captured in a dc:identifier/citation is the complete bibliographic record for the resource itself. This proposal is not concerned with capturing citation linking data for a related resource. Some background information about bibliographic citation information is in section 4.

This proposal does not make any recommendations about the encoding of the components of a bibliographic citation within a dc:identifier/citation element. A second proposal by the DCMI Citation Working Group, 'A Journal Article Bibliographic Citation Dublin Core Structured Value' [2], suggests an encoding scheme, but the two proposals are independent. Other possible encodings could be an OpenURL [3] or a plain text string.

2. The Proposal

It is proposed that bibliographic citation information for a journal article, or similar bibliographic resource, should be captured within a dc:identifier element with a citation refinement.

2.1 Bibliographic Resource Identification

Using dc:identifier as the element in which to encode bibliographic citation information for a resource recognises the fact that this citation information effectively identifies that resource.

Consideration has been given to the appropriateness of other elements for capturing this information, in particular dc:description and dc:relation. Reasons for not recommending these elements are given below in section 4.

2.2 A citation Qualifier

It could be argued that a citation qualifier is not necessary, and that the information could be encoded in dc:identifier without this qualifier. This especially could be the case where the citation information is encoded according to a standard scheme which implies that the value is bibliographic citation information. But there are several advantages to using an explicit citation qualifier when encoding this type of information in dc:identifier:

3. Examples

3.1 Dublin Core Record for a Journal Article

This is an example of a Dublin Core record for a journal article including its bibliographic citation information. This example is independent of any syntax recommendation. Any syntax used in this example is for clarification purposes only.

dc:title = Studying E-journal User Behavior Using Log Files
dc:creator = Lu, Y
dc:creator = Apps, A
dc:subject(scheme=DDC) = 020
dc:description = Statistical methods for analysing e-journal user behaviour.
dc:publisher = Pergamon
dcterms:issued(scheme=W3CDTF) = 2000
dc:type(scheme=DCMIType) = text
dcterms:medium(scheme=IMT) = application/pdf
dc:identifier(scheme=URI) = doi:10.1060/xyz.abc
dc:identifier(scheme=URI) = urn:sici:07408188(200010)22:3<311:SEUB>2.0.CO;2-X
dc:identifier/citation = {
  Journal Title = Library and Information Science Research
  Journal Abbreviated Title = LISR
  Journal Volume = 22
  Journal Issue Number = 3
  Journal Issue Date = October 2000
  Pagination = 311-338
dc:language(scheme=RFC1766) = en
dcterms:isPartOf(scheme=URI) = urn:issn:0740-8188
dc:rights = © Elsevier, 2000

In the following example, only the bibliographic citation information is given.

3.2 A Plain Text Journal Article Citation

The bibliographic citation information for the above article may be encoded within its Dublin Core record, using plain text, in an xhtml meta tag as follows, assuming that the new citation element refinement will be in the dcterms namespace. This plain text string could choose to follow some publication convention.

<meta name="dcterms:citation"
content="Library and Information Science Research 22(3), 311-338 (2000)" />

The same bibliographic citation information encoded in HTML would be:

<meta name="DC.Identifier.citation"
content="Library and Information Science Research 22(3), 311-338 (2000)">

4. Bibliographic Citations

This section describes the bibliographic citation information for a journal article, but similar considerations would apply to capturing within existing Dubin Core elements the citation information for other types of bibliographic resource.

4.1 Journal Article Bibliographic Citation Properties

The properties generally used to capture the bibliographic citation of a journal article may be identified at three distinct levels: the Journal level; the journal Issue level (which may also include a journal Volume level); and the individual Article level. The following table indicates these properties according to this hierarchical level, and where appropriate which Dublin Core element is already available to record the information.

Level Property DC Element
Journal Journal Title
Journal Abbreviated Title
Journal Identifier
Issue Volume
Article Article Title dc:title
Author dc:creator
Publisher dc:publisher
Publication Year dc:date
Publication Date dc:date
Identifier dc:identifier

It is apparent from this table that there is currently no method within Dublin Core to capture the bibliographic citation of a journal article, except by recording the information in an ad hoc way within a dc:description element, or by capturing the metadata in a hierarchical manner.

4.2 Other Possible Solutions

4.2.1 Using dc:description

The advantages of the dc:description solution would be to retain the essential simplicity of Dublin Core, and that the information would be presented to someone discovering the metadata in a human-readable way. The latter point is important, and any solution should provide data to a human end-user in a readily understandable form - they may wish to find the article on a library shelf. The disadvantage of using dc:description is that it becomes difficult to perform further machine processing on the discovered metadata, which may be required for discovery of the location of the article.

4.2.2 A Hierarchical Solution

It would be possible to partially record the information in a hierarchical way, using a dc:relation element to point from an article record to a record for its containing issue, and similarly from the issue record to that for the containing journal. There are two drawbacks to this solution:

It could be thought that including information about a journal in the metadata for an article breaks the `one-to-one' rule. However the objective here is not to provide information about the journal, but rather to provide a bibliographic citation of an article, which effectively identifies it.

4.2.3 An Application Profile

Another possible method for including in a metadata record information which doesn't fit obviously into one of the 15 elements of the Dublin Core element set (DCMES), or the ratified qualifiers, is to introduce application specific elements and qualifiers within an application profile [5]. Thus an option would be to define a `citation' profile and include new elements such as `journal title' within it. However, capturing bibliographic citation information seems to be a generic, cross-domain problem. The bibliographic citation of a journal article is fairly fundamental information, required within many subject areas, at least for academia and researchers. It is information which is becoming increasingly significant with the implementation of linking technologies. Therefore it would seem sensible to have a best practice convention for capturing journal article citation information within Dublin Core metadata using existing elements, rather than a proliferation of application profiles attempting to solve the same problem in different ways with new application specific elements.

4.3 Previous Work

How to record a bibliographic record for a journal article has previously been discussed by an earlier Dublin Core Citation Working Group, whose recommendation made after the DC7 Workshop was 'Citation Qualifier Proposal - 2000' [6], which also includes details of a vote by the general DC community at the plenary session at the DC8 Workshop.

5. References

[1] DCMI Citation Working Group. http://www.dublincore.org/groups/citation
[2] A Journal Article Bibliographic Citation Dublin Core Structured Value. http://epub.mimas.ac.uk/DC/citdcsv.html
[3]NISO Committee AX: Development of an OpenURL Standard. http://library.caltech.edu/openurl/
[4]Voting during the Plenary session at DC8. http://www.dublincore.org/groups/citation/citqualifier2000.html#dc8vote
[5] Heery, R. and Patel, M. (2000) Application profiles: mixing and matching metadata schemas. Ariadne 25, September 2000. http://www.ariadne.ac.uk/issue25/app-profiles
[6] Citation Qualifier Proposal - 2000. http://www.dublincore.org/groups/citation/citqualifier2000.html