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> bf:workTitle with domain=bf:Work
> 
> makes these two statements equivalent, although in #2 you must first infer the type of :X from the predicate "bf:workTitle":
> 
> :X a bf:Work ;
>   bf:worktitle [blah] .
> 
> :X bf:workTitle [blah] .
> 
> In both cases, the type of :X is bf:Work.


This is predicated on the operation of an inference regime, presumably RDFS or stronger. It is not true under plain RDF entailment.

It's important to notice that assumption when it comes into play. RDF processing does not normally make it, because it is expensive, the expense varying with the strength of inference regime. For a strong regime and for applications that require processing with strong guarantees about response time, the expense can be prohibitive. It is possible to make inference a requirement for Bibframe applications, but I agree with Rob Sanderson: that would be a mistake. It should be possible for a machine to process Bibframe without engaging such machinery, and I say that even though I believe very strongly that inference is the most important frontier for these technologies.

---
A. Soroka
The University of Virginia Library

On Nov 6, 2014, at 2:46 PM, Karen Coyle <[log in to unmask]> wrote:

> 
> On 11/6/14 8:00 AM, Simon Spero wrote:
>> On Nov 6, 2014 10:10 AM, "Karen Coyle" <[log in to unmask]> wrote:
>> 
>> > If the bf:workTitle were of type bf:Work instead of bf:Title, you would get:
>> >
>> > <X> rdf:type bf:Work .
>> > <X> bf:workTitle _:aa .
>> > _:aa rdf:type bf:Work .
>> > _:aa bf:titleValue "Here's my title" .
>> >   
>> > Does that clear it up?
>> 
>> Ah- now I think I understand-when you are talking about a property being of a certain type, you are talking about the range of the property, not the type of the property itself (ie the thing named bf:workTitle. Did it clear up? :-)
>> 
> 
> No, actually, I'm talking about the domain of properties, not the range. The domain of the property asserts "instance of class" on the subject of the property relation. So 
> 
> bf:workTitle with domain=bf:Work
> 
> makes these two statements equivalent, although in #2 you must first infer the type of :X from the predicate "bf:workTitle":
> 
> :X a bf:Work ;
>   bf:worktitle [blah] .
> 
> :X bf:workTitle [blah] .
> 
> In both cases, the type of :X is bf:Work.
> 
> For others, perhaps, note that an subject (":X" here) can be of more than one type. So there's nothing wrong with saying:
> 
> :X a bf:Work;
>    a bf:mapType;
>    a bf:digitalObject .
> 
> if you want to do that. And those types could either be explicit ("a bf:xxx") or inferred. The latter could take advantage of something like 
> 
> bf:coordinates domain=mapType
> bf:digForm domain=digitalObject
> 
> And an instance that goes like:
> 
> :X a bf:Work;
>    bf:coordinates "blah" ;
>    bf:digForm <URI-for-PDF> .
> 
> That's probably not how you'd do forms, but it's the example that came to mind.
> 
> What this does mean is that you have to be careful what domains you define for your properties, because they add semantics to your     subjects. (The most visible way to test this, IMexperience, is by defining classes as disjoint and then mixing properties from those classes in a single graph. Reasoners come back with an "inconsistent" conclusion, telling you your data doesn't match your ontology.)
> 
> kc
> 
> 
> 
>> If the range of workTitle is declared to Work, then the value of the property as well as the subject of the property would also be an instance of bf:Work.
>> 
>> Is a goal to treat titles as Works in their own right, and to be able to have titleValue asserted directly on X?
>> 
>> Is a goal to find triples that may be reachable from  instances of Work? In that situation, SPARQL 1.1 sub queries or property paths may do some of the work.
>> 
>> Outside of SPARQL, some approaches to serving linked data return closely related entities alongside the base object, trading off bandwidth for latency or server load. id.loc.gov does this quite a bit ;the work on linked data fragments looks to combine this with client side query processing.
>> 
>> Simon
>> 
> 
> -- 
> Karen Coyle
> 
> [log in to unmask] http://kcoyle.net
> 
> m: +1-510-435-8234
> skype: kcoylenet/+1-510-984-3600
>