- From: Frank Manola <fmanola@mitre.org>
- Date: Sun, 17 Aug 2003 16:18:44 -0400
- To: pat hayes <phayes@ihmc.us>
- CC: w3c-rdfcore-wg@w3.org
pat hayes wrote: > Frank Manola wrote: > >> Argh! I hope the Primer isn't misleading on this question, because I >> don't think your last sentence is accurate. What I try to say is that >> rdf:ID provides a way of indicating that, in addition to generating >> the usual triple, a reification of that triple with a specific URIref >> (generated from the rdf:ID value) is to be generated as well. It >> doesn't (I don't think) "attach a URI reference to a triple in an >> RDF/XML document". > > > Well, isn't that attachment done by the fact of the URI appearing in the > rdf:ID in the document in question? But OK, I could rephrase it thus: > > (In the RDF/XML syntax described in RDF/XML Syntax Specification > (Revised) [RDF-SYNTAX] the use of rdf:Id with a URI reference as value > creates a reification of the enclosed triple, with that URI reference as > the reified triple.) > > Would that be better? Its more awkward but maybe more accurate. > > Pat > Pat-- What I'm getting at is what I say later in the Primer reification section: "Using rdf:ID as shown in Example 20 generates the reification automatically, and provides a convenient way of indicating the URIref to be used as the subject of the statements in the reification. Moreover, it provides a partial "hook" relating the triples in the reification with the piece of RDF/XML syntax that caused them to be created, since the value triple12345 of the rdf:ID attribute is used to generate the URIref of the subject of the reification triples. However, this relationship is once again outside RDF, since there is nothing in the resulting triples that explicitly says that the original triple had the URIref exproducts:triple12345 (RDF does not assume there is any relationship between a URIref and any RDF/XML that it might have been used or abbreviated in)." That is, if you look at the graph (Figure 17), there's nothing that connects the triple described by the RDF/XML ("the enclosed triple") to the URIref used in the reification triples (generated from the rdf:ID attribute value). So there's sort of an "attachment" between the generated graph and some RDF/XML, but the interpretation of that attachment is still strictly outside of RDF. I just wouldn't want anyone to interpret this parenthetical remark (whatever text it contains) as an exception to or qualification of the original statement that there isn't really a connection defined by RDF. This would be an application-dependent convention that related (in a specific way) the resulting graph to the RDF/XML used to generate it; and this information wouldn't necessarily be available to a second party receiving the graph. NB: "rdf:Id with a URI reference as value" isn't strictly accurate either. rdf:ID ("ID" in caps) doesn't take a URIref as a value; its value is used (as a fragment id) to *construct* a URIref. --Frank >> --Frank >> >> pat hayes wrote: >> >>> >>> After reading Frank's Primer text, I have changed some text in the >>> reification section 3.2.1 of Semantics from this: >>> >>> "Although RDF applications may use reification to refer to triple >>> tokens in RDF documents, the connection between the document and its >>> reification must be maintained by some means external to RDF. RDF >>> syntax provides no means to 'connect' an RDF triple to its >>> reification. " >>> >>> to this: >>> >>> "Although RDF applications may use reification to refer to triple >>> tokens in RDF documents, the connection between the document and its >>> reification must be maintained by some means external to the RDF >>> graph syntax. (The RDF/XML syntax described in RDF/XML Syntax >>> Specification (Revised) [RDF-SYNTAX] provides rdf:Id to attach a URI >>> reference to a triple in an RDF/XML document, and create the >>> corresponding reification.) " >>> >>> I hope the WG does not object to this; I think the rather sharp >>> negative was misleading. >>> >>> Pat >>> >> >> >> -- >> Frank Manola The MITRE Corporation >> 202 Burlington Road, MS A345 Bedford, MA 01730-1420 >> mailto:fmanola@mitre.org voice: 781-271-8147 FAX: 781-271-875 > > > -- Frank Manola The MITRE Corporation 202 Burlington Road, MS A345 Bedford, MA 01730-1420 mailto:fmanola@mitre.org voice: 781-271-8147 FAX: 781-271-875
Received on Sunday, 17 August 2003 15:54:01 UTC