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Re: Why Literals should be unique and why this is a serious issue

From: Andreas Andreakis <andreas.andreakis@gmx.de>
Date: Sat, 19 Nov 2005 11:19:48 +0100
Message-ID: <437EFC44.3040102@gmx.de>
To: Richard Newman <r.newman@reading.ac.uk>
CC: semantic-web at W3C <semantic-web@w3c.org>

this is a good example.

The scenarion you describe is a matter of modelling and at last related 
to resource-identification. For instance, If you describe an Ontology 
with persons having the same name, you simply have to add
more inverse functional properties (in owl) to identify persons. And 
dont forget that in terms of resource identification it is a 
prerequirement to assume a specific class and not only literals, since 
literals themselfs can not talk detailed about a resource they describe. 
What does "Tiger" mean ? OS, Animal oder somekind of other Product ? or 
what does "David Green" alone mean ? a company name oder a person name ?

The FOAF Ontology uses for instance a combination of 2-3 
inv-funct-properties do identify persons, where the email is of of those.

But anyway, we have still not solved the dublication-problem and talking 
around will not bring us forward. So I ask again. And Im really looking 
forward to suggestions from you guys.
How can we prevent this ?
People are lazy and will not search if others have created somethink 
simmilar. Higher levels of abstractions can prevent dublications, but we 
need a unified specification on this ! There are already Implementations 
that ignore rdf:IDīs of resources, the most common example is FOAF. FOAF 
says in its specification, not to include rdf:IDīs, so where will this 
lead us ? If the one uses IDīs and ther other inverse-funct-properties ??


Richard Newman schrieb:

> Let's have a counter-example.
> I know two people named David Green. Almost no literal-valued  
> property can really be termed inverse-functional: even genetic code  
> sequences can be shared (between twins, for example). Certainly,  
> terming names ("Tiger Woods") as IFPs (your more "fundamental  
> problem") doesn't work.
>> So, in a relational Database this problem would have never arrised.  
>> So why canīt be do the same in Ontologies ?
> Well, as has been pointed out, we can -- IFPs. We don't do so very  
> often because our assertions have global scope, and I *know* that the  
> two David Greens are separate individuals.
> Relational databases rarely choose to deal with the possibilities of  
> integrating data from a dozen sources.
> -R
Received on Saturday, 19 November 2005 10:20:55 UTC

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