RE: ISSUE-148: RDF Concepts - IRIs do *not* always denote the same resource

On Saturday, December 14, 2013 7:54 PM, Pat Hayes wrote:
> Possible wording compromise....
> 
> On Dec 14, 2013, at 8:26 AM, David Booth <david@dbooth.org> wrote:
> > On 12/14/2013 07:04 AM, Markus Lanthaler wrote:
> >>
> >>   . IRIs have global scope by design. Thus, two different appearances
> >>     of an IRI denote the same resource. Violations of this principle
may
> >>     lead to interoperability problems or inconsistencies when, e.g.,
> >>     using data from multiple sources.
> >>
> >> Would that address your concerns?
> >
> > That comes *very* close to addressing my concerns.  A slight tweak to
> > the bullet item would do it:
> >
> >   . IRIs have global scope by design. Thus, two different appearances
> >     of an IRI are intended to denote the same resource. Violations
> >     of this principle may lead to interoperability problems or
> >     inconsistencies when, e.g., using data from multiple sources.
> 
> >> IRIs have global scope by design. Thus, two different appearances
> >>     of an IRI should denote the same resource.  <etc.>

I find this similarly confusing than David's proposal. If IRIs have global
scope by design then all other cases are violations. "Should" or "are
intended to" is, IMO, too weak in this case. Just because that constraint is
sometimes violated in practice doesn't mean that the spec should be written
in such a way. All RDF 1.1 specifications are based on this fundamental
property of IRIs. If we make this too weak here, all other specifications
are affected by this as well. The <> IRI in the following two triples MUST
be the same in order for the two triples to make any sense:

  <> rdf:type foaf:Person .
  <> foaf:name "Markus".


> Pat
> 
> PS it even works if you put it in upper case.

RFC2119 keywords don't make much sense in a non-normative section. That
being said, what are the "valid reasons in particular circumstances to
ignore" this constraint?



--
Markus Lanthaler
@markuslanthaler

Received on Sunday, 15 December 2013 12:31:25 UTC