- From: Bernard Vatant <bernard.vatant@mondeca.com>
- Date: Wed, 08 Nov 2006 13:40:13 +0100
- To: "Williams, Stuart (HP Labs, Bristol)" <skw@hp.com>
- Cc: public-esw-thes@w3.org
Hello Stuart Seems that you got quickly what subject indicators are all about. Congratulations! :-) Some precisions to mail it. > Ok... so the relationship between a topic and a subject indicator is > functional. > I guess you mean "inverse functional" here. - A topic can have more than one subject indicator - Two topics which have at least one subject indicator in common are representing the same subject (and should be merged in a fully processed topic map) The relation between topic and *subject* is functional : a topic represents a single subject. Which means when a topic has more than one subject indicators, they all indicate the same subject > That makes the example I tried to contrive very bogus. > Indeed, but useful for clarification. > So... in topic map terms... is a skos:Concept also a tm:Topic. I think > the answer is probaly yes. > More or less. See a very good introduction to RDF vs TM by Lars Marius Garshol, who is certainly the one to have gone deep in the details of this. http://www.ontopia.net/topicmaps/materials/tmrdf.html > An appropriate subject indicator (as you say) > would be a (single?) document that describes the subect in clear an > unambiguous terms. > > I question the single, because there could be multiple unambiguous > accounts of given subject and reaching common agreement that one was in > some sense primary over the others would be 'tricky'. You're right. There is no technical way to prevent people to mint different subject indicators for the same subject. Either they are not aware there is already one available, or they don't trust it, or they prefer to have one in their own namespace, whatever. Same problem as people minting different URIs for the same concept, actually. > It's almost as if > the subject indicator ought to be an intervening (possibly blank) node > off of which multiple accounts could be 'hung'. > Absolutely. This is the second level of indirection we have been discussing with Mark. And actually in the introduction to Published Subjects in XML Topic Maps book, I was already suggesting that a subject indicator could be a kind of empty hub, taking its meaning from resources linked through it. > Ok... I've got the point (I think). skos:subjectIndicator is (or should > be) functional - though I remain mildly trouble about the potential for > multiple clear, independently fashioned and unamiguous accounts of the > same subject eg. Isaac Newton from the intro to the document referened > above. > You are right. Subject indicators are pushing the question of identification and same-ness a step further in the recursivity loop. Bernard
Received on Wednesday, 8 November 2006 12:40:29 UTC