Comments on: W3C Semantic Web = Global Ontology after all?

By: Eric Jain

Eric Jain — Thu, 13 Dec 2007 07:50:25 +0000

Don’t think the two opinions conflict: “all RDF documents containing a URI should use it to identify the same concept” != “the same concept should be identified by the same URI in different RDF documents”…

By: Phil Dawes

Phil Dawes — Thu, 13 Dec 2007 09:43:51 +0000

That’s true, but for semantic interoperability the same URIs need to feature in the communication somewhere - whether directly or via relationships defined in owl.

By: Jan

Jan — Thu, 13 Dec 2007 15:08:13 +0000

I don’t get your point, Phil. As long as “global ontology” != “a single, predefined, giant ontology” [1]. Everything should be all right, or not?

[1] - http://www.w3.org/2001/sw/SW-FAQ#whgiantont

By: Stephen Reed

Stephen Reed — Thu, 13 Dec 2007 16:27:08 +0000

During the DARPA DAML project, which funded MIT’s Semantic Web efforts at the time, Tim Berners-Lee envisioned the RDF web to unfold in a manner similar to the HTML web. Each development group would create an ontology (RDF taxonomy) independent of other groups. And that situation came to pass. A foaf:Person means the same thing as a cyc:Person but they have different URIs. The Linked Data initiative seeks to map these concepts together from various published ontologies, thus advancing the Global Ontology. For my own work, I am using the comprehensive OpenCyc ontology and extending it where needed.
-Steve
texai.org

By: Jim Hendler

Jim Hendler — Fri, 14 Dec 2007 03:53:16 +0000

Phil - I think you’re missing the point - think of it as one namespace for all those URIs vs. many namespaces — that is, in one case we’d all have to agree that “http://ex.com/foo#fish” was a particular thing with particular properties and etc, vs. allowing different people to have different ideas about what “fish” are - by keeping the info at different URIs and linking them together. So someone can define a vocabulary with some set of properties, someone else who disagrees, can do another, concepts can be linked or not, etc. In the “We all agree to one thing and sing kumbaya” ontology view, we must get all sorts of people from different cultures and approaches and views and religions and and and to all agree to everything - seems pretty daunting, right? On the other hand, the Semantic Web (i.e. web of semantic concepts) let’s many different ones coexist, one can extend another, they can disagree, they can be simple or complex as needed, and they, most important of all, because of the URIs can be linked into a global whole — but that global whole is not going to be consistent, carefully organized, and agreed to by everyone - and that’s the key point we’re trying to make. Note that this is related, but somewhat different, than what Steve Reed said - the linking of common terms is a piece of it, but the ability to have local agreement and real differences, that’s not traditional to the knowledge approach - and requires new technologies and approaches, which is where RDFS and OWL come in…

By: Phil Dawes’ Stuff » Blog Archive » URIs are syntactically universal, not semantically universal

Sat, 15 Dec 2007 21:05:51 +0000

[…] to all who commented to my previous post, it’s made me rethink and clarify my position on the problems with scaling Semantic Web […]