June 26, 2007

dc.source — an attempt to clarify why it is not something else (updated 1.40 pm)

Filed under: Dublin Core,MARC,Repositories — Neil Godfrey @ 2:41 am

Librarians and their clients are used to thinking of sources as citations. And this carries over into confusion in the Dublin Core metadata world.

We are used to thinking of a bibliographic or cited “source” for an article, but in MARC “source” can mean an actual institution or donor who provided the material (tag 037 for “source of acquisition) and in DCMI it can mean the page or book from which an article was scanned.

Like any term the word “source” is used differently depending on perspectives of users.

The following DCMI links may help clarify the DC meaning and use of their term “source” in their elements.

The DCMI definition of source is “Information about a second resource from which the present resource is derived”, and they give 2 examples:

  1. a page from which a picture was copied;
  2. a call number of a book from which a pages were scanned.

In repositories especially we are depositing works by authors that are subsequently published in journals etc. So strictly speaking in this case the author is the source, though obviously we use ‘creator’ or ‘contributor’ in this case. And the publishing journal title is a subsequent related title. That journal might be a “source” of info for a student later on, but it is not the “source” of the original article itself, which is what repositories are dealing with, and which DC is attempting to isolate with this term.

And the whole thing gets more confusing when, as one of our partners commented, one uploads a postprint, a publisher’s version of a document. Is not the publishing journal title then the ‘source’ while this would not be the case with a pre-print. Obviously this gets damn messy if we are going to be martinets about semantics. We naturally want a single source whether the document is a preprint or a postprint. But the confusion of this particular example also demonstrates why the publishing “journal title” cannot be the actual dc.source. And this leads in to the MARC mapping from the host or publishing journal. . . .

Relation to the MARC 773 (or 787) tag

The mapping of the Host Item Entry MARC 773 to dc.relation is based on the standard LOC and DC crosswalks for these. One example is at

This conforms with the standard DCMI definition of relation. Note that the LOC standard description for 773 is “host item” and that too indicates a “relationship” to the document being archived in the repository. A more complete 773 field with page references for the article identified in the subfields technically turns the 773 into a “dc.identifier”. But no need to go there for now.


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