[OAI-implementers] Reconsidering mandatory DC in OAI-PMH

Matthew Cockerill matt@biomedcentral.com
Tue, 5 Aug 2003 14:00:31 +0100


The Dublin Core spec page says:
http://dublincore.org/documents/dces/

'The Dublin Core metadata element set is a standard for cross-domain
information resource description. Here an information resource is defined to
be "anything that has identity". '

i.e. the point about Dublin Core is that it is not tied to a specific
semantic domain.
http://www.ukoln.ac.uk/metadata/resources/dc/datamodel/WD-dc-rdf/

Re: RSS - RSS seems to be a bit of morass of competing approaches right now,
but my understanding is that Dublin Core is fairly central to most proposals
for enriching the semantics of RSS.
e.g. http://web.resource.org/rss/1.0/modules/dc/

I would argue that enforcing a baseline set of cross-domain metadata
semantics is *as* important an aspect of the OAI-PMH project as is the
protocol itself. 
(Although certainly, the two could be thought of as logically distinct
sub-projects]

Matt

> -----Original Message-----
> From: Sandro Zic [mailto:sandro.zic@zzoss.com]
> Sent: 05 August 2003 12:36
> To: Matthew Cockerill
> Cc: oai-implementers@oaisrv.nsdl.cornell.edu
> Subject: RE: RE : [OAI-implementers] Reconsidering mandatory DC in
> OAI-PMH
> 
> 
> Zitat von Matthew Cockerill <matt@biomedcentral.com>: 
> > But it still seems to be that having a baseline metadata 
> standard that *all* 
> > OAI providers must implement is an *extremely* useful aspect of the 
> > protocol.  
>  
> It is, but only where useful :) Think of OAI-PMH in the 
> Weblogging world, to 
> do some sophisticated RSS harvesting. DC is not used there, 
> instead they 
> disucss about RSS 1.0, RSS 2.0, RDF-based RSS, Echo, etc. to 
> achieve metadata 
> interoperability. 
>  
> OAI-PMH is very powerful as a generic protocol for metadata 
> harvesting, it 
> should not IMHO concentrate on metadata interoperability, instead on 
> interoperability on the protocol level. Finding standards for 
> metadata 
> exchange on the metadata level should not be a concern of 
> OAI-PMH as metadata 
> is bound to the semantic domain where OAI-PMH is being used. 
>  
> Sandro 
>   
> > e.g. It is currently possible to build tools which will 
> browse an arbitrary 
> > repository, and list the titles of the new items which were 
> added to the 
> > repository that day. If you remove the support for Dublin 
> Core metadata, 
> > then even such a simple task would become impossible (right ?). 
> >  
> > Does it really follow that removing the requirement for 
> Dublin Core support 
> > would increase the support for other, richer formats? 
> Surely the two things 
> > are independent, 
> >  
> > Matt 
> >  
> > == 
> > Matthew Cockerill Ph.D. 
> > Technical Director 
> > BioMed Central Limited (http://www.biomedcentral.com) 
> > 34-42, Cleveland Street 
> > London W1T 4LB 
> >  
> > Tel. +44 20 7631 9127 
> > Fax. +44 20 7580 1938 
> > Email. matt@biomedcentral.com 
> >  
> >  
> > > -----Original Message----- 
> > > From: Martin Sevigny [mailto:sevigny@ajlsm.com] 
> > > Sent: 05 August 2003 12:25 
> > > To: oai-implementers@oaisrv.nsdl.cornell.edu 
> > > Subject: RE : [OAI-implementers] Reconsidering mandatory 
> DC in OAI-PMH 
> > >  
> > >  
> > > > Carl Lagoze wrote 
> > >  
> > > > 2.  The linkage between Dublin Core and OAI-PMH has been  
> > > > over-emphasized 
> > > > at the expense of the utility of OAI-PMH for dissemination  
> > > of richer, 
> > > > and perhaps more useful, structured data.  In some cases data  
> > > > providers 
> > > > with richer metadata (e.g., MARC, IEEE LOM) have been 
> forced by the 
> > > > requirement to dumb-down rich metadata to Dublin Core 
> and have then 
> > > > failed to provide the original metadata.  As a result, 
> the community 
> > > > looses the benefits of rich data and is left with the reduced  
> > > > semantics 
> > > > of Dublin Core. 
> > >  
> > > I do strongly agree with this statement. Many times, I had to  
> > > go back at 
> > > the basics and try to convince people tha OAI-PMH could  
> > > transport other 
> > > XML data structures then DC. 
> > >  
> > > This strong association has been of great importance in 
> the early and 
> > > rapid adoption of OAI, because it (may) remove the burden of  
> > > agreeing on 
> > > data structure for exchange. But I think that since this 
> first step in 
> > > the adoption of OAI is now done, it would not cause too 
> much harm to 
> > > remove this constraint. 
> > >  
> > > > generalization.  Although removing the Dublin Core  
> > > > requirement would not 
> > > > negatively impact existing or future data providers, it 
> may impact 
> > > > service providers whose applications depend on the 
> existence of a 
> > > > uniform metadata format. 
> > >  
> > > This is the main drawback of it. I personnaly believe 
> that in a real 
> > > distributed, multilingual, multivocabulary environment 
> (very realistic 
> > > today), the benefits of having a common model as limited as  
> > > Dublin Core 
> > > are not that important. 
> > >  
> > > > 1. Change the Dublin Core requirement to a recommendation. 
> > >  
> > > Agreed. 
> > >  
> > > > 2. Leave oai_dc as a reserved metadataPrefix 
> > >  
> > > Yes, it should. 
> > >  
> > > > 3. Move the oai_dc part of protocol document to Implementation 
> > > > Guidelines 
> > >  
> > > OK. 
> > >  
> > > Martin Sévigny 
> > > AJLSM 
> > > sevigny@ajlsm.com 
> > >  
> > > _______________________________________________ 
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> > >  
> >  
> > 
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