I think the strength of adopting RDF is that it doesn't tie us to a single vocab/schema. That isn't to say it isn't desirable for us to establish common approaches, but that we need to think slightly differently about how this is done - more application profiles than 'one true schema'.

This is why RDA worries me - because it (seems to?) suggest that we define a schema that stands alone from everything else and that is used by the library community. I'd prefer to see the library community adopting the best of what already exists and then enhancing where the existing ontologies are lacking. If we are going to have a (web of) linked data, then re-use of ontologies and IDs is needed. For example in the work I did at the Open University in the UK we ended up only a single property from a specific library ontology (the draft ISBD http://metadataregistry.org/schemaprop/show/id/1957.html "has place of publication, production, distribution").

I think it is interesting that many of the MARC->RDF mappings so far have adopting many of the same ontologies (although no doubt partly because there is a 'follow the leader' element to this - or at least there was for me when looking at the transformation at the Open University)

Owen

Owen Stephens
Owen Stephens Consulting
Web: http://www.ostephens.com
Email: [log in to unmask]
Telephone: 0121 288 6936

On 5 Dec 2011, at 18:56, Jonathan Rochkind wrote:

> On 12/5/2011 1:40 PM, Karen Coyle wrote:
>> 
>> This brings up another point that I haven't fully grokked yet: the use of MARC kept library data "consistent" across the many thousands of libraries that had MARC-based systems. 
> 
> Well, only somewhat consistent, but, yeah.
> 
>> What happens if we move to RDF without a standard? Can we rely on linking to provide interoperability without that rigid consistency of data models?
> 
> Definitely not. I think this is a real issue.  There is no magic to "linking" or RDF that provides interoperability for free; it's all about the vocabularies/schemata -- whether in MARC or in anything else.   (Note different national/regional  library communities used different schemata in MARC, which made interoperability infeasible there. Some still do, although gradually people have moved to Marc21 precisely for this reason, even when Marc21 was less powerful than the MARC variant they started with).
> 
> That is to say, if we just used MARC's own implicit vocabularies, but output them as RDF, sure, we'd still have consistency, although we wouldn't really _gain_ much.    On the other hand, if we switch to a new better vocabulary -- we've got to actually switch to a new better vocabulary.  If it's just "whatever anyone wants to use", we've made it VERY difficult to share data, which is something pretty darn important to us.
> 
> Of course, the goal of the RDA process (or one of em) was to create a new schema for us to consistently use. That's the library community effort to maintain a common schema that is more powerful and flexible than MARC.  If people are using other things instead, apparently that failed, or at least has not yet succeeded.