- From: Stella Dextre Clarke <sdclarke@lukehouse.demon.co.uk>
- Date: Fri, 3 Jun 2005 09:40:17 +0100
- To: "'Miles, AJ \(Alistair\)'" <A.J.Miles@rl.ac.uk>, <public-esw-thes@w3.org>
No comment on why or how to sort out the matter Alistair has raised, but in case you find it useful, here are some examples of how arbitrary the "immediate parent" can be. The first is from EMTREE: "cattle bovids artiodactyla ungulate placental mammals mammal vertebrate Shown below is the subtly different entry for "cattle" in the CAB Thesaurus. These examples illustrate that the concept of hierarchical level in thesauri is relative, not absolute, and that the choice of levels is driven by perceived user needs, not theoretical principles. In other words, the presence of a BT/NT relationship, even if the convention BT1, BT2, etc. is used to distinguish between levels, does not indicate what semantic distance separates the pair of linked terms. In different thesauri, a case could be made for giving the immediate BT of cattle as ruminants, or as mammals, or as animals. from CAB Thesaurus (1995 edition): Cattle BT1 Bos BT2 Bovidae BT3 ruminants BT4 artiodactyla BT5 mammals " The above is an extract, by the way, lifted from my chapter on Thesaurus Relationships in the 2001 book by Bean and Green on "Relationships in the Organization of Knowledge" Cheers 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: 02 June 2005 19:41 To: public-esw-thes@w3.org Subject: RE: SKOS Extensions ... broaderDirect/narrowerDirect ... ? N.B. this does beg the question as to whether skos:broader and skos:narrower should themselves be transitive, given that everyone will use them to make their assertions, or should rather not be transitive themselves but have super-properties that are transitive. Food for thought. Cheers, Al. --- 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 Miles, AJ > (Alistair) > Sent: 02 June 2005 19:33 > To: public-esw-thes@w3.org > Subject: SKOS Extensions ... broaderDirect/narrowerDirect ... ? > > > > Hi all, > > The properties skos:broader and skos:narrower are transitive. > This means that in an open world, it's impossible to know > whether one concept is the immediate parent of another, which > makes e.g. building tree representations hard. One way > around this is to define sub-properties of > skos:broader/skos:narrower that are not transitive, and use > these to make assertions. > > Given this requirement, I was thinking of putting a couple of > properties into the SKOS Extensions Vocabulary [1] called > something like 'broaderDirect' and 'narrowerDirect' ... any > objections? > > Cheers, > > Al. > > [1] http://www.w3.org/2004/02/skos/extensions/spec/ > > --- > 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 > > >
Received on Friday, 3 June 2005 08:40:18 UTC