- From: Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk>
- Date: Fri, 9 Sep 2011 17:24:56 +0100
- To: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
- Cc: Satya Sahoo <satya.sahoo@case.edu>, public-prov-wg@w3.org
On Fri, Sep 9, 2011 at 16:37, Luc Moreau <L.Moreau@ecs.soton.ac.uk> wrote: >> RDF-wise we I think we would need to express these attributes outside >> the regular graph. > What do you mean by regular? I meant the RDF graph that the the assertions from the provenance account/container have been serialised in. (We have assumed one graph per account/container to avoid stating everything with reification). Those graphs could be separate provenance resources on the web, or part of a named graph serialisation. > I tend to talk about application data, and if we make the application > provenance-aware, we also have provenance data. > Is your regular graph, the application data graph? No, it's the provenance graph. >> For instance with anonymous nodes and prov:wasCharacterisedBy : > Is wasCharacterisedBy a relation that has been previously defined by the WG > or is it your proposal here? Had to make it up! Sorry for not clarifying that. It might be a construct we need only in the ontology, unless we need to change the model to have the characterisation separate as well. > OK, I think this would encode the atttributes of an entity. We > need to make sure that there is only one wasCharacterizedBy per entity. I agree, that would make it like a primary key and solve many problems as the anonymous graph can't be extended (except through owl:sameAs which we then probably should not use). >> Probably more sensible is to make prov:wasCharacterisedBy a >> subproperty of prov:wasComplementOf as that would be true anyway. >> (right?) > Hhm, really? Perhaps not - if we assume that anything stated about within :e1 wasCharacterisedBy is also true directly for :e1, and we also make the range of wasCharacterisedBy be an Entity which is characterised by itself (what else?), then :e1 is a complement of the anonymous node, as it has all the same characterised attributes locked down. But perhaps that's not very useful - why would we want the characterisation to be an entity? >> would not be allowed. It says Literal, so not even URIs? >> entity(e3, [ owner:<http://id.ecs.soton.ac.uk/person/391> ]) > I think this part of the spec needs to be discussed here. It's related > to the question of domain specific data. What about the attribute names? Would it be reasonable to assume that any URI would do, and that they are data/object properties in RDF? (Would reasoning on those be allowed, say Simon brings in some subproperties?) >From the model's definition we could just RDFize it as a collection of key-value pairs - but I don't think that would be as useful as using regular properties. It would however be useful in formats like XML and JSON. Key-values in RDF/N3 (Using prov:hadAttributes instead of prov:wasCharacterisedBy): :e1 a prov:Entity ; prov:hadAttributes ( [ prov:attributeName "company"; prov:attributeValue "Toyota" ], [ prov:attributeName "model"; prov:attributeValue "Corolla" ], [ prov:attributeName "identification"; prov:attributeValue "1a" ] ) . or JSON: { "entities": { "e1": { "company": "Toyota", "model": "Corolla", "identification": "1a" } "e2": { .. } } } This raises questions about namespacing, as these keys are used for characterising things. > What is interesting about named graphs here, is that they "freezed" the set > of attributes we want to assert for a given entity. Yes, and you could tell if two entities are describing the same thing by ensuring both graphs are equivalent. (something for the RDF WG - I believe this is already formalised). I am however the named graph could be misunderstood as "Snapshot of everything true about the entity when making the provenance". -- Stian Soiland-Reyes, myGrid team School of Computer Science The University of Manchester
Received on Friday, 9 September 2011 16:25:49 UTC