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Re: URI lifecycle (Was: Owning URIs)

From: Kingsley Idehen <kidehen@openlinksw.com>
Date: Wed, 20 May 2009 12:59:15 -0400
Message-ID: <4A1436E3.8050802@openlinksw.com>
To: David Booth <david@dbooth.org>
CC: John Graybeal <graybeal@mbari.org>, semantic-web <semantic-web@w3.org>, Linked Data community <public-lod@w3.org>
David Booth wrote:
> Hi John,
>
> Re: "The URI Lifecycle in Semantic Web Architecture":
> http://dbooth.org/2009/lifecycle/
>
> On Tue, 2009-05-19 at 10:46 -0700, John Graybeal wrote:
>   
>> *Very* interesting paper, for the content and for the links.   
>> Addresses many a topic I've been trying to sort out.
>>
>> If I may ask for a clarification on a few key points at the beginning:
>>
>> 1) At what point does 'minting' occur?  (a) When I think of the URI,  
>> (b) when I first write it down as a string in some file, (c) when I  
>> 'serve' it in some formal way, (d) when I make a statement that  
>> references it, or (e) ...? You define it as 'establishing the  
>> association between the URI and the resource it denotes', but how does  
>> the process of establishing that association occur, exactly? It all  
>> seems a little imprecise with respect to real-world resources.
>>     
>
> The simplest answer is that the URI is minted when the URI owner
> publishes its URI declaration, since it is the URI declaration that
> establishes the association between the URI and the resource it denotes.
>
>   
>> 2) Am I correct in thinking the URI owner is just the person who has  
>> the authority to create a URI (and optionally provide an initial set  
>> of statements about it)? In the SW, the idea of someone having the  
>> "authority" to link their URI to the actual resource -- Earth's moon  
>> for example -- is confusing, since many people will mint URIs meant to  
>> refer to the Earth's moon; I think they all have that authority, in  
>> some sense. (AWWW focused more on the actual URI and information  
>> resources, where there is an implicit association, often through  
>> deferencing.)
>>     
>
> In simple terms, the URI owner is the owner of the domain from which the
> URI is allocated, or the owner's delegate.  For example, if John owns
> domain foo.example.com then John is the owner of all URIs allocated
> within that domain, such as http://foo.example.com/bar/whiz/bang .
> However, John could delegate minting authority to all or part of his URI
> space.  For example, John could delegate minting authority for all URIs
> matching http://foo.example.com/lucinda/* to Lucinda.  
>   
David,

What about describing this in terms of: Data Space or URI Space ownership?

You are describing functionality that should be integral to any Data 
Space or URI Space platform that plugs into the Internet ?

Kingsley
> The notion of URI ownership is defined in the AWWW section 2.2.2.1:
> http://www.w3.org/TR/webarch/#uri-ownership
>
>   
>> 3) Can you define a "core assertion"?  If I can improve my assertions  
>> to clarify that I meant the Earth moon we all know about, as opposed  
>> to some other 'Earth moon', is that not allowed per R1? How do we know  
>> when an improvement makes the original concept more useful, as opposed  
>> to erroneous for some users? (Note your suggestion later that "it's OK  
>> when expectations are properly set", a la SKOS.)
>>     
>
> The core assertions are merely those that are provided in the URI
> declaration and serve to define the association between the URI and a
> resource.  They do so by constraining the permissible "interpretations"
> for that URI.  (An "interpretation" in RDF semantics lingo maps URIs to
> resources.)  In the end the question of whether a change in a URI
> declaration will be helpful or harmful to your users is a judgement
> call.  In theory, any change to the core assertions has the potential of
> invalidating some user's code.  However, in practice some changes are
> far less likely to cause problems than others, because they don't affect
> the set of permissible interpretations -- at least not in a way that
> matters.  For example, in the moon example at
> http://dbooth.org/2007/uri-decl/#example
> changing the rdfs:seeAlso assertion is unlikely to break users' code
> because it doesn't really constrain the resource identity of the URI
> http://dbooth.org/2007/moon/ .  
>
> One can think of the core assertions as constraining the set of
> permissible interpretations for that URI.  There will always be some
> ambiguity about what resource the URI denotes -- this is inescapable --
> but the core assertions clearly delineate that ambiguity.  This is
> further explained in a companion paper, "Denotation as a Two-Step
> Mapping in Semantic Web Architecture":
> http://dbooth.org/2009/denotation/
>
>   
>> The paper is a nice encapsulation of many of the idiosyncrasies of the  
>> current state of the social practice. Thanks
>>     
>
> You're welcome.  And thanks very much for your comments!
>
>
>   

-- 


Regards,

Kingsley Idehen	      Weblog: http://www.openlinksw.com/blog/~kidehen
President & CEO 
OpenLink Software     Web: http://www.openlinksw.com
Received on Wednesday, 20 May 2009 16:59:55 UTC

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