- From: Kingsley Idehen <kidehen@openlinksw.com>
- Date: Wed, 20 May 2009 12:59:15 -0400
- 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 16:59:56 UTC