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Fwd: Correct Usage of rdfs:idDefinedBy in Vocabulary Specifications with a Hash-based URI Pattern

From: KangHao Lu (Kenny) <kennyluck@w3.org>
Date: Fri, 22 Oct 2010 00:05:20 +0900
Cc: ML public-lod <public-lod@w3.org>, Tim Berners-Lee <timbl@w3.org>
Message-Id: <5E0B6F8C-106B-45CA-9574-06A69559B77E@w3.org>
To: Martin Hepp <martin.hepp@ebusiness-unibw.org>
Hello Martin,

I don't think my argument would be very logical, but we can't wait for  
rule engines to discuss this.

> Note, however, the majority of the Web vocabularies use the same URI  
> for the entity name reference and the descriptor reference, see the  
> link provided by Michael Hausenblas:
>
> 	http://code.google.com/p/void-impl/issues/detail?id=45
>
> and in particular the little survey by Richard Cyganiak posted on  
> that page.
>
> I personally would argue that in the case of ontologies /  
> vocabularies, the conceptual difference between the entity and the  
> descriptor is a lot less significant than when it comes to data,  
> since an ontology is, by definition, a specification, i.e. a document.
>

Basically I like this approach, that is, I don't like the fact that  
some ontologies have '#' as end character and there should not a URI  
for an ontology document and a different URI for the *conceptual*  
ontology.

IIRC, 3 years ago Tim was very shocked by those ontologies that have  
'#' as end charter and claimed that this is not a good idea (and he  
would bring up this issue at TAG or awwaw, I can't remember). The  
argument was that string after '#' has the meaning of 'local  
identifier' (so that we use #I #i for WebIDs because 'I' is a 'local  
identifier') and identifiers can't be empty strings (or this might  
break some systems, I guess). I somehow agree with that, and Toby's  
use of "my:" to identify an Ontology makes me a little bit  
uncomfortable. I have no idea if there's any followup after Tim  
brought this to TAG or awwaw.

I have another argument, namely, you should distinguish the concept  
from the document only if the following criterion is satisfied.

- if the time when the thing with hash URI is created and the time  
when the document is created have *clear* difference

So this holds for people, so people should not use document URIs. This  
holds for organizations, cause you create the website of an  
organization maybe some years after the organization is founded.

The problem is 'ontology'. I don't know whether you should call the  
structure an ontology or it became an ontology once it is written  
down, but I don't think the difference of the timing is very *clear*.  
A similar example is when you want to give a URI to a python module. I  
would not end it with '#' because I don't see why we need do  
distinguish the 'module document' from 'module'. A module is a kind of  
document, so is ontology. So, owl:Ontology rdfs:subClassOf  
foaf:Document !

Well, this is a theory. If there's a common practice of using '#'- 
ending URI for ontologies, maybe we should accept it.

No strong opinion. Wasn't this discussed at AWWAW? Just curious.

Cheers,

--
Kenny
WebID: http://dig.csail.mit.edu/People/kennyluck#I
What is WebID: http://esw.w3.org/WebID
Received on Thursday, 21 October 2010 15:07:37 UTC

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