@prefix rdf: . @prefix ns1: . @prefix foaf: . ns1:this rdf:type foaf:Person . @prefix sioct: . rdf:type sioct:Weblog . @prefix atom: . rdf:type atom:Feed . @prefix rdfs: . rdfs:label "kidehen@openlinksw.com's BLOG [127] description" . rdf:type atom:Entry , sioct:BlogPost ; rdfs:label "State of the Linked Data Web" . rdf:type atom:Entry , sioct:BlogPost . @prefix dc: . dc:title "Library of Congress & Reasonable Linked Data" ; foaf:maker ns1:this ; rdfs:label "Library of Congress & Reasonable Linked Data" . @prefix dt: . @prefix dcterms: . dcterms:created "2009-05-05T13:53:24-04:00"^^dt:dateTime ; dcterms:modified "2009-05-06T14:26:15.000034-04:00"^^dt:dateTime . @prefix sioc: . sioc:id "f13c24a1a0c82a341b0d426f97368b01" ; sioc:link ; sioc:content "\nWhile exploring the Subject Headings Linked Data Space (LCSH) recently unveiled by the Library of Congress, I noticed that the URI for the subject heading: World Wide Web, exposes an "owl:sameAs" link to resource URI: "info:lc/authorities/sh95000541" -- in fact, a URI.URN that isn't HTTP protocol scheme based.\n\nThe observations above triggered a discussion thread on Twitter that involved: @edsu, @iand, and moi. Naturally, it morphed into a live demonstration of: human vs machine, interpretation of claims expressed in the RDF graph.\n\nWhat makes this whole thing interesting?\nIt showcases (in Man vs Machine style) the issue of unambiguously discerning the meaning of the owl:sameAs claim expressed in the LCSH Linked Data Space.\nPerspectives & Potential Confusion\n\nFrom the Linked Data perspective, it may spook a few people to see owl:sameAs values such as: "info:lc/authorities/sh95000541", that cannot be de-referenced using HTTP.\n\n\nIt may confuse a few people or user agents that see URI de-referencing as not necessarily HTTP specific, thereby attempting to de-reference the URI.URN on the assumption that it's associated with a "handle system", for instance.\n\nIt may even confuse RDFizer / RDFization middleware that use owl:sameAs as a data provider attribution mechanism via hint/nudge URI values derived from original content / data URI.URLs that de-reference to nothing e.g., an original resource URI.URL plus "#this" which produces URI.URN-URL -- think of this pattern as "owl:shameAs" in a sense :-)\n\nUnambiguously Discerning Meaning\n\nSimply bring OWL reasoning (inference rules and reasoners) into the mix, thereby negating human dialogue about interpretation which ultimately unveils a mesh of orthogonal view points. Remember, OWL is all about infrastructure that ultimately enables you to express yourself clearly i.e., say what you mean, and mean what you say.\n\nPath to Clarity (using Virtuoso, its in-built Sponger Middleware, and Inference Engine):\n\nGET the data into the Virtuoso Quad store -- what the sponger does via its URIBurner Service (while following designated predicates such as owl:sameAs in case they point to other mesh-able data sources)\nQuery the data in Quad Store with "owl:sameAs" inference rules enabled \nRepeat the last step with the inference rules excluded.\n\nActual SPARQL Queries:\n \n\n SPARQL Query against the HTTP based Subject Heading URI for WWW\n\n\n SPARQL Query (with reasoning via inference rule for owl:sameAs) against the URN based Subject Heading URI for WWW\n\n SPARQL Query (*without* reasoning via inference rule for owl:sameAs) against the URN based Subject Heading URI for WWW\n\nObservations:\n\nThe SPARQL queries against the Graph generated and automatically populated by the Sponger reveal -- without human intervention-- that: "info:lc/authorities/sh95000541", is just an alternative name for < xmlns="http" id.loc.gov="id.loc.gov" authorities="authorities" sh95000541="sh95000541" concept="concept">, and that the graph produced by LCSH is self-describing enough for an OWL reasoner to figure this all out courtesy of the owl:sameAs property :-).\nHopefully, this post also provides a simple example of how OWL facilitates "Reasonable Linked Data". \n\nRelated\n\n\n State of the Linked Data Web\n\n\n Making Linked Data Reasonable Using Description Logics Series - post by Mike Bergman\n\n\n" ; atom:title "Library of Congress & Reasonable Linked Data" . @prefix ns10: . sioc:has_creator ns10:this ; sioc:has_container . @prefix ns11: . sioc:links_to ns11:concept . @prefix dbpedia: . sioc:links_to dbpedia:SPARQL , , . @prefix ns13: . sioc:links_to ns13:concept , , , , , , dbpedia:Uniform_Resource_Identifier , dbpedia:Web_Ontology_Language . @prefix ns14: . sioc:links_to ns14:iand , ns14:kidehen , , , ns14:edsu , . @prefix ns15: . sioc:links_to ns15:this , , dbpedia:Resource_Description_Framework , dbpedia:Uniform_Resource_Locator ; atom:source ; atom:author ns1:this ; atom:published "2009-05-05T17:53:24Z" ; atom:updated "2009-05-06T18:26:15Z" . @prefix opl: . opl:isDescribedUsing . ns10:this rdf:type sioc:User . @prefix rdf: . @prefix ns1: . @prefix foaf: . ns1:this rdf:type foaf:Person ; foaf:made . @prefix atom: . rdf:type atom:Feed . @prefix sioct: . rdf:type sioct:Weblog . @prefix rdfs: . rdfs:label "kidehen@openlinksw.com's BLOG [127] description" . @prefix sioc: . sioc:container_of ; atom:entry ; atom:contains . @prefix ns7: . ns7:this rdf:type sioc:User ; sioc:creator_of .