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Re: [Dbpedia-discussion] Using DBpedia resources as skos:Concepts?

From: Simon Spero <ses@unc.edu>
Date: Fri, 6 Nov 2009 14:31:12 -0500
Message-ID: <1af06bde0911061131x11513e1eva51470fc79a551cd@mail.gmail.com>
To: Pat Hayes <phayes@ihmc.us>
Cc: Leonard Will <L.Will@willpowerinfo.co.uk>, Alexandre Passant <alexandre.passant@deri.org>, Richard Cyganiak <richard@cyganiak.de>, dbpedia-discussion@lists.sourceforge.net, SKOS <public-esw-thes@w3.org>
On Fri, Nov 6, 2009 at 11:58 AM, Pat Hayes <phayes@ihmc.us> wrote:

>
> On Nov 5, 2009, at 4:05 PM, Simon Spero wrote:
>
> FWIW, I have no trouble with imaginary entities. Still, there is a clear
> distinction between the concept of a unicorn and a particular unicorn, eg
> the one depicted here: http://bit.ly/3Hgz0P
>

[...]

> Once one starts thinking extensionally this whole discussion becomes much
> easier ("Word and Subject?").
>
> For example:
>
> Everything that is-about something is a document.
> Everything that something is-about is a concept.
>
>
> My problem is that this second assertion is blatantly false. I have shelves
> full of books that are not about concepts at all. Biographies are about
> people, not (usually) concepts of people. So at this point, SKOS simply
> vanishes into never-never land. I have no idea what it is talking about
> (quite literally).
>

[To clarify, I am talking about standard Knowlege Organization System (KOS)
semantics, not SKOS directly].

The second assertion is an axiom...

The problem we're having here is that the word "Concept" has different
meanings in different disciplines.   An alternative term used in the
Knowledge Organization literature is "Subject".  That term can lead  to even
worse confusion, especially in the context of RDF, but is used to good
effect by Elaine Svenonius in the following quote:

Subject language terms differ referentially from words used in ordinary
language. The former do not refer to objects in the real world or concepts
in a mentalistic world but to subjects. As a name of a subject, the term
Butterflies refers not to actual butterflies but rather to the set of all
indexed documents about butterflies. (Svenonius 2000, p. 130)

This is an allusion to Leonard Cohen's "How to speak poetry":

The word butterfly is not a real butterfly. There is the word and there is
the butterfly. If you confuse these two items people have the right to laugh
at you.

The importance of Svenonius's  distinction can be seen by considering the
relationship between two Subjects. Let's stick with our examples, and choose
the strings "Unicorns" and "Pictures of unicorns".

As ordinary language, these strings refer to  different "kinds" of things.
One refers to the set of horses with horns;  the other refers to the set of
pictures of horses with horns. These sets are completely disjoint.

Now consider what these strings refer when treated as subjects.  One string
refers to the set of all documents about horses with horns;  for example,
the novel "The black unicorn".  The other strings refers to the set of all
documents about pictures of horses with horns; for example, a wiki page
containing a list of freely usable pictures of unicorns.

These two sets are both sets of documents.  Not only are the two sets  not
disjoint; the second set is a subset of the first.

A similar relationship can be seen between the strings "Horses" and
"Diseases in horses".

I'm  leaving "aboutness" underspecified, but one could probably get away
with treating it in terms of assignments of indexing terms to documents to
which a "native speaker" (i.e. expert indexer) of the subject language would
assent.

Simon
------
Svenonius, Elaine (2000). The Intellectual Foundation of Information
Organization. Cambridge, Mass.: MIT Press.
Received on Friday, 6 November 2009 19:31:52 GMT

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