- From: Bradley Allen <bradley.p.allen@gmail.com>
- Date: Tue, 5 Jul 2011 10:23:43 -0700
- To: Gregg Kellogg <gregg@kellogg-assoc.com>
- Cc: Kingsley Idehen <kidehen@openlinksw.com>, "public-linked-json@w3.org" <public-linked-json@w3.org>
Allow me to jump into the breach here with a reworded set of points that attempt to capture Kingsley's feedback: 1. Linked Data is a set of documents, each containing a representation of a linked data graph. 2. A linked data graph is a labeled directed graph, where nodes are subjects or objects, and edges are properties. 3. A subject is any node in a linked data graph with at least one outgoing edge. 4. A subject MAY be labeled with an IRI. 5. A property is an edge of the linked data graph. 6. A property SHOULD be labeled with an IRI. 7. An object is a node in a linked data graph with at least one incoming edge. 8. An object MAY be labeled with an IRI. 9. An IRI that is a label in a linked data graph SHOULD be dereferencable to a Linked Data document describing the labeled subject, object or property. Bradley P. Allen http://bradleypallen.org On Tue, Jul 5, 2011 at 10:12 AM, Gregg Kellogg <gregg@kellogg-assoc.com> wrote: > Kingsley, thanks for the feedback. > > If you're requiring as a basic precept that every URI used in an LD graph be de-referencable, this would leave out statements of the set of URIs that are not de-referencable. This would seem to also include URNs. I don't think it's appropriate to limit JSON-LD to use only de-referencable URIs. However, I do believe that a best practice (where feasible) is to use de-referencable URIs, where a suitable representation is returned. > > Otherwise, can you suggest a re-wording of the LD points in [1] that would be more accurate? > > Gregg > > [1] http://json-ld.org/requirements/latest/#linked-data > > On Jul 5, 2011, at 1:45 AM, Kingsley Idehen wrote: > >> On 7/5/11 7:09 AM, Manu Sporny wrote: >>> Topic: Formal Definition of Linked Data >> First assertion about Linked Data reads: >> Linked Data is used to represent a directed graph . >> >> Sorry, but that's back to front, at best. >> >> A directed graph used to represent (describe) an object can be >> constructed in such a way that subject name, subject attributes, and >> subject attribute values take the form of de-referencable URIs. >> >> In the case of Linked Data, specifically, a URI de-references to a >> representation of its Referent. It does this because an Object has >> Identity distinct from its Representation. Thus, an Object has a Name >> that's distinct from the EAV/SPO graph pictorial that delivers its >> description (representation). Naturually, on the Web (as is the case >> with a computer's local OS), said representation exists as the content >> of a Resource at a location (Address). >> >> Of course, you don't have to accept my definition of Linked Data. But >> note this, bar different turn of phrase, I've just outlined the very >> essence of TimBL's original Linked Data meme prior to the regressive >> tweak that added "(RDF* and SPARQL)" to its later revision. The day >> "(RDF* and SPARQL)" are dropped from the meme or described as >> implementation details is the day that meme returns to its GOLDEN status >> IMO. >> >> At this juncture, the JSON-LD definition of Linked Data is inaccurate. >> >> You can make graphs that aren't Linked Data purveyors. Thus, don't >> conflate graphs and linked data, let alone application of the linked >> data concept to a global data space such as the WWW. The specific use of >> URIs as part of graph construction is integral to what linked data is >> about. >> >> From RDF to JSON-LD conflation remains a problem. Conflation ultimately >> breeds confusion. >> >> The pieces of the puzzle: >> >> 1. Graphs -- an effective data structure fine grained data representation >> 2. de-referencable URIs -- critical data structure tapestry (remember a >> URI isn't implicitly de-referencable, the URL subClassOf URI is) >> 3. Resources -- data (collections of eav/spo triples) containers >> accessible from addresses. >> >> Current list of conflation examples: >> >> 1. Resources -- everything is a resource meme is inaccurate since it >> dangerous ignores perception media (WWW and Real World are related but >> distinct media) >> 2. Graphs -- RDF is the only mechanism for graph representation or that >> graph means RDF rather than RDF being an option for graph based data >> representation >> 3. Linked Data -- to the RDFer Linked Data and RDF are one and the same >> 4. JSON-LD -- Linked Data is either a subset of RDF or its used to >> represent directed graphs. >> >> Sincerely hoping these comments are digested. I have but a single goal: >> kill off conflation so we can make progress re. InterWeb scale Linked >> Data without forcing syntax or data serialization formats on anyone. >> Openness isn't as easy as folks assume. To be truly open you have to >> invest heavily in the significant costs associated with choice. >> >> >> -- >> >> Regards, >> >> Kingsley Idehen >> President& CEO >> OpenLink Software >> Web: http://www.openlinksw.com >> Weblog: http://www.openlinksw.com/blog/~kidehen >> Twitter/Identi.ca: kidehen >> >> >> >> >> >> > > >
Received on Tuesday, 5 July 2011 17:24:21 UTC