Comment on Formal Semantics: attribution element semantics

Comment on http://www.w3.org/TR/2008/WD-powder-formal-20080709/, Formal 
Semantics

[[[
POWDER-S (Semantic POWDER)

     The Semantic encoding uses a fragment of RDF/OWL that has been 
extended in a way that facilitates the matching of the string 
representation of a resource's identifier against a regular expression....
]]]

then, later (in Section 2.2):

[[[
Since the attribution element provides data about the document itself, 
it is transformed from POWDER (through POWDER-BASE) into POWDER-S as an 
RDF Description for which the value of the rdf:about attribute is null.
]]]

There is a mixup here of RDF/OWL as a model and its serialization in XML 
(namely RDF/XML). rdf:about is _not_ an RDF (model) notion, but a 
particular attribute in the RDF/XML serialization (I know, it is a bit 
confusing, sorry about that...:-).

the problem is, of course, that we do not have a standard for named 
graphs (alas!). One of way of solving that is to specify from the start 
that the whole spec is geared at RDF/XML only, but that is, obviously, 
not nice.

Alternatively, some careful wording (I do not have one from the top of 
my head, unfortunately) might say that those annotations refer to the 
specific POWDER-S graph and this is expressed in RDF/XML with the "" value.

Yet another, slightly more complex but more standard possibility is to 
use the owl:Ontology element

http://www.w3.org/TR/owl-ref/#Ontology-def

specifying that the Ontology header refers to the generated POWDER-S 
graph (and, indeed, in most of the cases, the rdf:about will be "" on 
that ontology, too).

I tend to opt for some more careful wording...:-)

Ivan

-- 

Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
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