- From: Karen Coyle <kcoyle@kcoyle.net>
- Date: Fri, 11 Jul 2014 14:32:29 -0700
- To: "Peter F. Patel-Schneider" <pfpschneider@gmail.com>, Jose Emilio Labra Gayo <jelabra@gmail.com>
- CC: "public-rdf-shapes@w3.org" <public-rdf-shapes@w3.org>
On 7/11/14, 12:56 PM, Peter F. Patel-Schneider wrote: > I'm still trying to figure out how shape expressions can constrain the > shape of RDF graphs. Yes, they can constrain the shape of a RDF graph > flowing out of a single source, but that's only part of the problem. > Another part, and one that I think is much more important, is > constraining the "shape" of nodes that belong to a particular class. Classes are orthogonal to shapes -- classes are semantic, shapes are syntactic. The Description Set Profile [1], which was an XML schema model for creating shapes with RDF, tried to address that (and I think it's worth looking at). That project was perhaps premature and never completed, but I am still convinced that the need to define the shape of our data exists. And shaping - as the DSP does - requires a big picture of your data. Much validation looks at individual "bits" but there is also a need to formulate and test large, complex structures, in addition to individual statements. If this capability does not exist in ShEx then we need to add it. kc [1] http://dublincore.org/documents/dc-dsp/ > > So, again, how can I describe those RDF graphs where every node that has > an rdf:type link to :GraduateStudent has at least one :university triple > and the object of such triples have an rdf:type link to > :ResearchUniversity? > > peter > > > On 07/11/2014 12:39 PM, Jose Emilio Labra Gayo wrote: >> On Fri, Jul 11, 2014 at 7:02 PM, Karen Coyle <kcoyle@kcoyle.net >> <mailto:kcoyle@kcoyle.net>> wrote: >> >> >> >> On 7/11/14, 9:31 AM, Jose Emilio Labra Gayo wrote: >> >> I mean, OWL and Shape Expressions have different goals...with >> OWL you >> model an ontology of concepts, while with Shape Expressions >> you just >> describe the shapes of RDF graphs. >> >> >> Jose, do you see them as complementary, perhaps working together? >> In other >> words, is a solution needed that checks both OWL(-type) inferences >> AND the >> shapes of the graphs? (I'm trying to get at the overall scope of >> the need.) >> >> >> Yes, definitely. >> >> In my point of view, OWL is very good at semantic level while Shape >> Expressions are more suited for the syntactic level or data >> integration level. >> >> Peter's example: "the spouse of every person is a person" seems for me >> more at >> the semantic or domain model level...and I would probably model it in >> OWL. >> >> In practice, if you have information like: >> >> :john :spouse :mary . >> >> and the previous declaration in OWL, the system could infer that :mary >> is a >> Person and if there were some declarations saying that mary is not a >> person, >> the system would detect an inconsistency. >> >> Apart from that, if you have a data portal about people, you may be >> interested >> to say that a resource has the shape of a Person and has some >> properties, like >> ":spouse", "foaf:name", etc. In this case, you are describing the RDF >> graph >> that you are publishing or that someone can consume from your data >> portal... >> >> I think the motivations for declaring the Shape Expressions of a data >> portal >> are very pragmatic and I have found that they cover a need for RDF data >> publication, consumption and integration...but of course, they are >> complementary with having OWL ontologies. >> >> Best regards, Jose Labra >> >> >> >> kc >> >> -- >> Karen Coyle >> kcoyle@kcoyle.net <mailto:kcoyle@kcoyle.net> http://kcoyle.net >> m: 1-510-435-8234 <tel:1-510-435-8234> >> skype: kcoylenet >> >> >> >> >> -- >> Saludos, Labra > -- Karen Coyle kcoyle@kcoyle.net http://kcoyle.net m: 1-510-435-8234 skype: kcoylenet
Received on Friday, 11 July 2014 21:32:59 UTC