RE: [Proposal][SKOS-Core] handling top concepts

Alistair,
So far as I can make out, the way you have handled this in your proposal
is absolutely fine, with "hasTopConcept" described as a property of the
scheme. The only problem I had was with calling this property a
"relation" or "relationship". In the thesaurus tradition,
"relationships" operate between terms or concepts, not between a scheme
and its contents.
Stella
*****************************************************
Stella Dextre Clarke
Information Consultant
Luke House, West Hendred, Wantage, Oxon, OX12 8RR, UK
Tel: 01235-833-298
Fax: 01235-863-298
SDClarke@LukeHouse.demon.co.uk
*****************************************************



-----Original Message-----
From: Miles, AJ (Alistair) [mailto:A.J.Miles@rl.ac.uk] 
Sent: 19 August 2004 18:20
To: 'Stella Dextre Clarke'; public-esw-thes@w3.org
Subject: RE: [Proposal][SKOS-Core] handling top concepts


> 
> 
> Not so much an objection as a puzzlement. Leonard's message
> of 7 August
> clarified that we thesaurus builders think of relationships 
> as existing
> between terms or concepts rather than existing between 
> concepts and the
> vocabularies that include the concepts. So if there is an attribute
> "hasTopConcept" we would expect that to be a way of expressing the
> widely used inter-term relationship called "Top Term" and abbreviated
> "TT". 
> 
> Example:
> 	Cattle
> 	  BT Mammals
> 	  TT Animals
> 	  NT Heifers

Hopefully potential confusion can be averted by some clear documentation
(I'm on it :)  Also, a SKOS validator will pick up misuse of the
skos:hasTopConcept property.

> 
> Some thesauri have displays which present the whole thesaurus as a set

> of hierarchies under all the Top Terms present. (And the number of top

> terms is typically in the hundreds or more, unless very general top 
> terms such as "Entities" and "Properties" are employed).  It is useful

> to be able to identify all the top terms in the thesaurus, so that you

> can easily present one of these displays. So I suppose you could say 
> that the top terms were in some way attributes of the thesaurus. 
> (Although I would normally think of them as content items rather than
> attributes) But I certainly don't see "having a top term (or concept)"

> as being a relationship between a scheme and a concept.

Maybe it would make more sense to think of a statement like 'concept A
is a top concept in scheme X'?  The statement 'schemeX
skos:hasTopConcept conceptA' says the same thing, but the other way
around.

> 
> By the way, a scheme must have at least one term (concept) in it to 
> exist at all, and that term, if alone, would be a top term (concept). 
> In other words, no such thing as a scheme that has no top terms
> (concepts).

It is true that the skos:hasTopConcept property simply gives you a way
of explicitly stating something that could be inferred, if we could
operate under a closed world assumption.  

But the semantic web is an open world, which means that 'topness' needs
to be stated explicitly. 

[Btw the closed world assumption is this: if something is not stated, it
is
assumed to be false.  Logic experts - I did get that right didn't I?]


> 
> Perhaps "relationship" means something different in the RDF world? 
> Rather unlucky when that world meets the thesaurus world and we try to

> cross-communicate!

I think we've managed to understand each other pretty good so far :)

Al.


> 
> Stella
> 
> *****************************************************
> Stella Dextre Clarke
> Information Consultant
> Luke House, West Hendred, Wantage, Oxon, OX12 8RR, UK
> Tel: 01235-833-298
> Fax: 01235-863-298
> SDClarke@LukeHouse.demon.co.uk
> *****************************************************
> 
> 
> 
> -----Original Message-----
> From: public-esw-thes-request@w3.org 
> [mailto:public-esw-thes-request@w3.org] On Behalf Of Miles, AJ
> (Alistair)
> Sent: 11 August 2004 17:33
> To: 'public-esw-thes@w3.org'
> Subject: RE: [Proposal][SKOS-Core] handling top concepts
> 
> 
> 
> Any last objections before I action this proposal [1] ?
> 
> Al.
> 
> [1] 
> http://lists.w3.org/Archives/Public/public-esw-thes/2004Aug/0002.html
> 
> ---
> Alistair Miles
> Research Associate
> CCLRC - Rutherford Appleton Laboratory
> Building R1 Room 1.60
> Fermi Avenue
> Chilton
> Didcot
> Oxfordshire OX11 0QX
> United Kingdom
> Email:        a.j.miles@rl.ac.uk
> Tel: +44 (0)1235 445440
> 
> 
> 
> > -----Original Message-----
> > From: public-esw-thes-request@w3.org
> > [mailto:public-esw-thes-request@w3.org]On Behalf Of Dave Beckett
> > Sent: 10 August 2004 13:57
> > To: Dan Brickley
> > Cc: Miles, AJ (Alistair) ; 'Supekar, Kaustubh S.'; 
> > 'public-esw-thes@w3.org'
> > Subject: Re: [Proposal][SKOS-Core] handling top concepts
> > 
> > 
> > 
> > On Wed, 4 Aug 2004 12:09:20 -0400, Dan Brickley
> <danbri@w3.org> wrote:
> 
> > ...
> > 
> > > Thanks, this identifies a discomfort I've had w/
> > interactions between
> > > 'top concept' notion and thesaurus mixing. At heart you're saying 
> > > 'top concept' is a relation between a a
> scheme/dataset/thesaurus and
> > > a concept. Makes sense to me.
> > 
> > This is why I suggested skos:hasTopConcept to Alistair.  You can't
> > promote one concept to 'top' in a shared web, since it 
> might not be a
> > top concept in another thesaurus in the same graph.  It is a
> > relationship between the thesaurus and some concept(s).
> > 
> > > So would this be:
> > > 
> > > <owl:FunctionalProperty
> > rdf:about="http:///....../skos/core#hasTopConcept"/>
> > > 
> > > ie. anything that has a skos:hasTopConcept has only one
> such thing?
> > 
> > No.  It may be 0 or more.  But if such a relationship exists it 
> > should be between the skos:ConceptScheme and some skos:Concept.  We 
> > had to pick a direction and it is most useful if it is written down 
> > (in rdf/xml say)
> > near the skos:ConceptScheme where other thesaurus-specific 
> information
> > is recorded since if you are considerign the thesarus
> itself, you want
> > to see the general items about it - such as top concepts - if
> > the exist.
> > Hence skos:hasTopConcept rather than skos:topConceptIn
> > 
> > Dave
> > 
> 
>

Received on Friday, 20 August 2004 09:58:39 UTC