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Perhaps we do not "constrain" in the usual data processing sense, but useful information can be mechanically derived using these technologies.

If I apply some ontology to a knowledge base and do not thereafter discover a certain resource X categorized into a certain type T, I normally interpret that in an open world as meaning that I just don't yet know whether X is a T. But, for my own convenience and within the privacy of my own systems, I _can choose_ to interpret that absence to myself to mean that X is not a T, as long as I don't publish this assertion or any assertions derived therefrom. It doesn't seem reasonable to me to ignore this possibility for workflow. 

It is also very possible to reinterpret OWL with formal closed-world semantics: Clark & Parsia offer a nice example at: http://docs.stardog.com/icv/icv-specification.html

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A. Soroka
The University of Virginia Library

On Jun 7, 2014, at 4:58 PM, Karen Coyle <[log in to unmask]> wrote:

> There is, however, a bit of a problem with writing profiles and their constraints in RDF -- which is that RDF (and OWL) support inferences, but not constraints in the usual data processing sense. If you've looked into the W3C validation work, or the DCMI AP work, you see that there are points where one either bends the RDF rules, or moves into another language with different semantics.
> 
> W3C validation: http://www.w3.org/2012/12/rdf-val/
> DCMI RDF APs: http://wiki.dublincore.org/index.php/RDF-Application-Profiles
> Shape Expressions: http://www.w3.org/2013/ShEx/Primer
> 
> The DCMI group is going to be looking into APs from the DCMI point of view. I'm personally not sure what this is going to require, but in trying to think through how it might be defined in RDF, I run into problems, especially with cardinality and anything requiring structure.
> 
> kc
> 
> On 6/7/14, 7:14 PM, [log in to unmask] wrote:
>> I have just learned about the Bibframe Profiles.
>> 
>> Since Bibframe is based on RDF, why are Bibframe Profiles not based on RDF?
>> 
>> As I understand, the constraints described in Bibframe Profiles are constraints on RDF elements and vocabularies, and do not constrain mere data. I'm not sure about what is meant with "structural constraints", maybe also integrity constraints?
>> 
>> So expressing Bibframe Profiles in RDF as rules would be more beneficial to the semantic web community.  I think it is possible to express the rules as an ontology. By doing this, informal notations or plain JSON or EBNF notations would no longer be necessary to express a Bibframe Profile, the document could be rewritten to use RDF (serialized in Turtle, JSON-LD, etc. whatever is convenient)
>> 
>> Best,
>> 
>> Jörg
> 
> -- 
> Karen Coyle
> [log in to unmask] http://kcoyle.net
> m: 1-510-435-8234
> skype: kcoylenet