Re: Mistaken identity?

Jon Hanna wrote:

>> Just because you use a particular URI as an rdf identifier doesn't
>>  automatically mean that the rdf resource is equal to the web page 
>> returned when you dereference the uri.
> No, it is equal to the resource a representation of which is returned
>  when you dereference the URI.

No, sorry, but that just isn't so.  Let me quote from one of the RDF
Recommendations, the RDF Semantics document -

"The semantics does not assume any particular relationship between the
denotation of a URI reference and a document or Web resource which can
be retrieved by using that URI reference in an HTTP transfer protocol,
or any entity which is considered to be the source of such documents."

It goes on to say this -

"Such a requirement could be added as a semantic extension, but the
formal semantics described here makes no assumptions about any
connection between the denotations of URI references and the uses of
those URI references in other protocols."

> Knowledge of the predicate <> is needed to 
> work out what this is, ...

That is certainly the case, and my example did feature the property 
"danny:URL".  That would be a privately-defined predicate.  But then, 
all predicates except for the basic ones defined in the rdf and rdfs 
specs are privately-defined. in the sense that they are not "officially" 
specified.  One would hope for an eventual standard or common practice 
that would codify some basic properties like this one.

In the topic map world, they would be called PSIs, "Published Subject 


Tom P

Thomas B. Passin
Explorer's Guide to the Semantic Web (Manning Books)

Received on Wednesday, 23 June 2004 02:11:15 UTC