Karen,
I suspect the members of the small coterie that could explain this are
all on vacation at this time. I am not in that group, but I will attempt
an explanation anyway ;-)
Reading the dcterm:subject entry, I can see that there is an expectation
that the term will be part of a context -- the context may be an
authoritative list that it must come from, or it could be a combination
of a list and rules, such as one gets with LCSH, LCC or Dewey. Any term
that gets a value from a context like that is considered non-literal in
the DCAM sense because the context needs to be included in the formal
description of the term. This is somewhat like the 6XX fields in MARC
where the indicator (or $2) tells you which vocabulary the subject
heading belongs to.
That said, this definition seems to exclude the possibility of
uncontrolled subject terms, which you mention. Leaving aside the DCAM
(which is often puzzling), it seems to me that you need a way to
indicate 1) whether or not the values in the subject field are
controlled and 2) if they are controlled, what list they come from. I
don't think that DCTERMS alone provides this capability, although you
could possibly create it by using these value "patterns":
1) a character string alone. This would represent an uncontrolled
subject term or terms.
2) A URI for the subject term. This is only an option if the term itself
has a URI. I can imagine URIs for things like LCC or Dewey looking
something like:
http://www.oclc.org/dewey/ddc22/973.13
3) A URI for the subject *system* plus a string for the subject heading
or term.
http://www.nlm.nih.gov/mesh/ "Dipeptidyl-Peptidase IV Inhibitors"
I'd love to hear other takes on this because I think it probably has
been amply discussed in the DC development process.
kc
Karen Arcamonte wrote:
> I'm currently involved in the selection of standard fields for a metadata
> project and we have some fields that we are calling Dublin Core fields
> (Subject and Relation fields), but we are including free text or
> uncontrolled terms. I notice that the DC Subject and Relation fields are
> "intended to be used with a non-literal value." I'm not sure what this
> means. Is there anyone that can explain in simple terms? I've looked at the
> DCMI Abstract Model and I'm still not sure what they mean by "non-literal"
> value. Also, can you say you are using Qualified Dublin Core for some fields
> and Simple Dublin Core for other fields in an application profile?
>
>
--
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Karen Coyle / Digital Library Consultant
[log in to unmask] http://www.kcoyle.net
ph.: 510-540-7596 skype: kcoylenet
fx.: 510-848-3913
mo.: 510-435-8234
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