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From Dave Reynolds <>
Subject Re: I think I've got some pretty basic confusion with reading into models
Date Thu, 09 Dec 2010 23:09:31 GMT
Hi Benson,

Given that sketch of the process I don't see any particular advantage in 
explicitly importing the ontology into each graph. It would certainly 
not be harmful but doesn't seem necessary.

There doesn't seem to be any inference involved (the primary reason to 
worry about DL conformance). Process 1 can generate a bare graph, 
process 2 can store it and proces 3 can query and visualize the data 
without needing the ontology import. If you want to publish the data on 
the web as an OWL file then adding an import would be reasonable but can 
be done as part of the publication step and doesn't have to be 
maintained through the internal chain.

The small reasons to not include the imports during the internal process 
chain are:

(1) When you create OntModels over the graphs the ontology will be need 
to be loaded in from somewhere and will be included in queries over it 
(that's the point of import). This is an overhead and has the potential 
to cause problems if the link to the imported ontology breaks.

(2) The whole notion of imports is a document-oriented notion. It sounds 
like you do have document-centric processing mode with a separate graph 
for each processed source document. However, you may in the future be 
merging graphs and ending up with multiple ontology declarations in the 
merged graphcs can be unhelpful clutter.

So six of one, half a dozen of the other, YMMV.

FWIW in almost all applications I've developed I've not included 
explicit import statements in internal graph stores or procesing chains 
but have sometimes inserted them in published output.


On 09/12/2010 17:57, Benson Margulies wrote:
> Dave,
> Permit me to take this up one more conceptual level.
> So, here at Basis we have a named entity extractor, plus we have been
> dabbling in JAPE rules to build some relationship extraction, and we
> have a coref system coming on line.
> We want to represent the output of these things in RDF, and then do
> 'interesting' queries in the RDF we come up with, and we eventually
> want to extend to querying dbpedia.
> I read a few books and tutorials and concluded that it made sense to
> work OWL-ishly instead of with naked RDF. I flirted with Proton, but
> decided for now to use my own little ontology.
> The flow is that one process does all this NLP and derives RDF/OWL,
> one graph per source. The second process takes these graphs and wants
> to stuff them into a store. And the third will do queries and
> visualization. On another thread I'm borrowing Andy's neurons on the
> subject of choosing a tuple store.
> After reading your messages, my thought is that I need to add the
> import into 'process 1', I don't really need any model in 'process 2'
> if I'm just pushing RDF/XML from here to there, and that in process 3
> the big question is to pick a store.
> Can you give me a pointer to read up to conform to OWL/DL, which from
> your email seems like it's what I'm stumbling toward doing?
> Or do you care to give me a shove in some other direction altogether?
> thanks,
> benson

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