W3C home > Mailing lists > Public > semantic-web@w3.org > September 2014

Re: Micellaneous

From: Pat Hayes <phayes@ihmc.us>
Date: Wed, 17 Sep 2014 10:13:23 -0700
Cc: "Thierry BIARD, EIRL AMBESAS" <thierry.ambesas@gmail.com>, "semantic-web@w3.org" <semantic-web@w3.org>, "pragmaticweb@lists.spline.inf.fu-berlin.de" <pragmaticweb@lists.spline.inf.fu-berlin.de>
Message-Id: <C2316855-15AB-423E-A0E0-580F6B6F495A@ihmc.us>
To: Sebastian Samaruga <cognescent@gmail.com>

On Sep 17, 2014, at 9:30 AM, Sebastian Samaruga <cognescent@gmail.com> wrote:

> Thierry, thanks really for your time answering my emails. I didn't take the online course. Although I've spending some of my time in some kind of semantic (semiotic) metamodel for what I understand as knowledge representation..
> 
> I'm copying this mail to the liists.
> 
> For what I came with, the core concepts, borrowed from semiotics, are:
> 1. Concept
> 2. Thing
> 3. Sign
> 
> First, a Sign is an occurrence of a Thing in some context. For example, in RDF, some URI referring something that somehow exist.
> 
> A Thing is something that can exist and, given that notion, can appear in occurrences of some kind. A thing also aggregates all of its occurrences as they represent the Thing as a whole.
> 
> Finally, a Concept is an abstraction of a set of Things. Things are instances of Concepts and, again, which Concept they are instance of is context dependent. A Thing could be regarded as an occurrence of a Concept.
> 
> So, given that I begin with Things and I need a source of them I can begin with some RDF source without the need of any schema embedded in it. The URIs in the triples are Signs.

OK so far, although RDF does not support contexts, so a given IRI is assumed to denote the same thing everywhere it occurs. 

> Aggregating all occurrences of the same URI I came up with the Thing they represent.

? How does that work? What do you mean by 'aggregating'? And how can you know if you have all the occurrences of a given IRI, on the entire Web? (You can't possibly know this.)

> Then using a simple algorithm of which URIs share the same predicates I can infer the type of the URIs and came up with the Concepts.

That is not going to work, because you would also need to know the domain and range properties of those predicates, and that information is not always given explicitly. At the very least, you will need RDFS or OWL type reasoning here. 

> 
> Now, the meta model:
> The core concepts inherits from a Resource class. This parent class has the following methods:

"methods"? That term is not meaningful in RDF.

> 
> Resource::getSigns(Sign | Thing | Concept) : Occurrences of argument
> Resource::getThings(Sign | Thing | Concept) : Instances of argument
> Resource::getConcepts(Sign | Thing | Concept) : Classes / roles of argument.
> 
> Example data:
> aPerson :employment anEmployment (Signs)
> Peter :employment SalesDptManager (Thiings)
> Person, Employe :employment Employment, Position (Concepts)
> 
> So, care must be taken building an ETL RDF tool that populates this bindings in Resource instances, provides querying facilities and support the construction of entities which apply rules-transformation kind of behavior using 'template' resources.
> 
> Then the model should allow to build queries navigating Resource APIs like retrieving all the Concepts a Thing plays in a context, which Signs are instances of a given Thing in a given Concept context, etc.

To repeat, there are no contexts in RDF. 

I would strongly recommend that you read more about RDF and its intended semantics before proceeding. 

Best wishes

Pat Hayes

> 
> Best,
> Sebastian Samaruga..
> 

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Received on Wednesday, 17 September 2014 17:14:03 UTC

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