W3C home > Mailing lists > Public > public-rdf-wg@w3.org > May 2012

Re: Ambiguity of "RDF namespace" - was: Re: Contradicting definitions of "property"

From: Richard Cyganiak <richard@cyganiak.de>
Date: Wed, 9 May 2012 23:27:30 +0100
Cc: RDF Working Group WG <public-rdf-wg@w3.org>
Message-Id: <B36A3A8B-E775-484A-B187-C41E8259A852@cyganiak.de>
To: Thomas Baker <tom@tombaker.org>
Hi Tom,

On 9 May 2012, at 22:53, Thomas Baker wrote:
>> How about this other approach? There's no such thing as a ?namespace? in RDF.
>> Just avoid the term on its own ? it's a remnant of the old XML baggage. Some
>> of the other related XML terms that came along with it have proven to be
>> useful though: Some RDF syntaxes offer a way of associating ?namespace
>> prefixes? with ?namespace IRIs? in order to abbreviate IRIs; and there's
>> ?namespace documents? which describe the terms in an RDF vocabulary all of
>> whose terms start with the same IRI. The term ?namespace? on its own is just
>> a sloppy way of referring either to such an RDF vocabulary or to a namespace
>> IRI.
> 
> +1 - I like this!  Keep "namespace" as an adjective.  Discourage its use as a
> noun by saying that "namespace" has no formal meaning in RDF and that when used
> informally, usage is inconsistent.  And above all, avoid using "namespace" as a
> noun in the formal specs.

Sounds good to me.

>> Not sure what your point is.
> 
> Really only that the natural-language sentence can be understood in different
> ways (and mostly by people not attuned to what may be "validly inferred").  

Fair enough.

> But I see you have removed the section from Concepts 1.1 for folding into the RDF Schema document.

Yes. There will be an opportunity to go over the RDF Schema 1.1 document with a fine comb once Danbri has made a bit more progress on it :-)

>>> It is not incorrect, then, to use the same IRI both as a namespace IRI
>>> and to denote a vocabulary?
>> 
>> It's not incorrect and it is fairly common practice AFAICT.
> 
> And that's fine with me.  The confusing bit, I think, is that
> 
>    "namespace IRI" = "vocabulary IRI"
> 
> however
> 
>    "namespace" != "vocabulary"

Yeah. I hope that avoiding “namespace” helps to reduce the confusion.

>> (Strictly speaking, an RDF document doesn't even need to define any classes
>> or properties to be an OWL ontology. *Any* RDF document is a (degenerate) OWL
>> document. But that's just sort of an accident in the way OWL is defined.)
> 
> Also fine.  I do not think this necessarily belongs in RDF 1.1 but I'd love to
> see it clarified _somewhere_.

Let's see how the new Primer turns out, maybe it can explain this.

Thanks for patiently talking through all this — I think this has helped both of us to get our terminology straight(er) :-)

Best,
Richard
Received on Wednesday, 9 May 2012 22:28:01 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 16:25:48 GMT