- From: Matthew Leingang <leingang@math.harvard.edu>
- Date: Wed, 04 Aug 2004 19:15:23 -0400
- To: Graham Klyne <GK@ninebynine.org>, <www-rdf-interest@w3.org>
Thanks for the reference. It seems the recommendation there would be to create (for instance) relation classes like :Purchase and :Gift to be subclasses of :Acquisition, perhaps, and everything a subclass of "a relation between a person and some stuff," kind of like I had been modeling it originally. But "person" is unnecessarily restrictive and "stuff," too, so I still wonder what the difference is between that an an rdfs:Statement, where rather than subclass for every relation, you use a property, namely, the predicate. Is the problem that some agents might incorrectly induct from a qualified rdfs:Statements to an unqualified one? Luckily, I'm just playing here, but I'm still interested in doing it "right". --Matt On 8/4/04 6:36 PM, "Graham Klyne" <GK@ninebynine.org> wrote: > A recent draft [2] put out by the Semantic Web Best Practices and > Deployment Working Group [1] might have some useful ideas for you: > > #g > -- > > [1] http://www.w3.org/2001/sw/BestPractices/ > > [2] http://www.w3.org/TR/swbp-n-aryRelations/ > > > > At 16:42 04/08/04 -0400, Matthew Leingang wrote: > >> Hi all, >> >> Long time lurker, first time poster. >> >> I'm thinking about generating RDF from my Books [1] database to publish >> online (why not? :-). Books allows you store lots of data, not only about >> the book, but when you got it, who you loaned it to, etc. >> >> How does one best put something like "I have owned this book since August 1, >> 2004" in RDF? Without the date I could just say >> >> :me foaf:owns [a book:Book; book:isbn "012345678"] . >> >> (assuming we have a book schema someplace with a Book class and isbn >> property). With the date we have a qualification of the foaf:owns property. >> When implementing this first in python, I started creating >> "AgentObjectAssociation" classes for want of a better term. Then about a >> day later I realized that these AgentObjectAssociations were just subclasses >> of regular RDF triples. It seems, then, that you can do this by reifying >> the statement and adding whatever other properties & types you want: >> >> [a rdfs:Statement; >> rdfs:subject :me; >> rdfs:predicate foaf:owns; >> rdfs:object [a book:Book; book:isbn "012345678"]; >> a ical:Vevent; >> ical:dtstart "2004-08-01".] >> >> I don't know if this is a misuse of ical to talk about *any* event, not just >> one that one might schedule in a PIM tool. But another schema for events >> could be used if necessary. >> >> I recall from the one of the RDF TR's that the set of statements >> >> [a rdfs:Statement; rdfs:subject :a; rdfs:predicate :b; rdfs:object :c] >> >> doesn't necessarily have to imply :a :b :c (which is a good thing: >> "declaring 'Mission Accomplished' doesn't make it so"!) and that made me shy >> away from using qualified statements like this. But it seems useful. >> Another use would be to give the authority of a statement, so an agent can >> decide which one to accept: >> >> [a rdfs:Statement; >> rdfs:subject :LeeHarveyOswald; >> rdfs:predicate :killed; >> rdfs:object :JohnFKennedy; >> dc:creator :WarrenCommission >> ]. >> >> [a rdfs:Statement; >> rdfs:subject :Mafia >> rdfs:predicate :killed; >> rdfs:object :JohnFKennedy; >> dc:creator :OliverStone >> ]. >> >> Sorry if my N3 is off, but hopefully you get my drift. So I guess I'm >> asking is: is this "in or out of line" (to borrow the question of a previous >> poster)? Are there other ways to employ adverbial prepositional phrases >> like "since" or "according to" in RDF? >> >> Thanks for any help. >> >> --Matthew Leingang >> >> [1] http://books.aetherial.net/ >> >> -- >> Matthew Leingang >> Preceptor in Mathematics >> Harvard University >> >> URL: http://www.math.harvard.edu/~leingang/ >> vCard: http://www.math.harvard.edu/~leingang/vCard.vcf > > ------------ > Graham Klyne > For email: > http://www.ninebynine.org/#Contact > -- Matthew Leingang Preceptor in Mathematics Harvard University URL: http://www.math.harvard.edu/~leingang/ vCard: http://www.math.harvard.edu/~leingang/vCard.vcf
Received on Wednesday, 4 August 2004 19:17:06 UTC