- From: Leonid Ototsky <leo@mgn.ru>
- Date: Mon, 21 May 2007 01:16:10 +0600
- To: Tim Berners-Lee <timbl@w3.org>
- CC: SW-forum <semantic-web@w3.org>
Tim, Suppose it will be good to use "class of classes" and many very good foundations from the EPISTLE Core Model - http://www.tc184-sc4.org/wg3ndocs/wg3n1328/lifecycle_integration_schema.html (see the list of Entities on the left). Leonid Ototsky - http://ototsky.mgn.ru/it Âû ïèñàëè 20 ìàÿ 2007 ã., 23:07:50: > Begin forwarded message: > From: Tim Berners-Lee <timbl@w3.org> > Date: 2007-05-19 19:27:56 EDT > To: Chris Bizer <chris@bizer.de> > Cc: tabultor@csai.mit.edu > Subject: Linked data and rdf:type in dbpedia > Hi Chris. > That was a great session in Banff. > I'm looking now at a problem where the Tabulator sucks in huge > amounts of dbpedia. The problem is rather random rdf:type links > 1. My home page says: > <http://dbpedia.org/resource/Tim_Berners-Lee> = card:i. > 2. That causes tab'r to bring > in http://dbpedia.org/resource/Tim_Berners-Lee > which in turn says > <http://dbpedia.org/resource/Tim_Berners-Lee> > a <http://dbpedia.org/resource/Category:People_from_London>. > 3. That causes Tab'r to look up the > class Category:People_from_London > $ cwm http://dbpedia.org/resource/Category:People_from_London > This says a bunch of people whose have subject of that > <http://dbpedia.org/resource/Catherine_of_York> :subject <> . > which is fine, but it also says: > <> a </class/yago/person>, > > <http://dbpedia.org/resource/Category:English_people_by_county>, > <http://dbpedia.org/resource/Category:London>, > <http://dbpedia.org/resource/Category:People_by_city_or_town_in_England>, > :Concept. > Here I think the use of rdf:type is incorrect. The class > People_form_London is a class of people. It is a subclass of Person. > It has no simple relationship to London. (It is in fact an > owl:Restriction on property origin to value london, but I doubt if > you can generalize that across dbpedia). > English people by County *could* be a class of classes. > The tabulator assumes that every time it follows rdf:type it is > going meta: from classes to classes of classes, etc. It does this > as in every other case so far, there have been only a few levels > (like 2). > Currently, it can't use dbpedia as it pulls it memory-busting > amounts of it. It not even clear that the rdf:type links don't have > cycles. > Anyone using OWL with this data wil of course find t impossible > to deal with classes of classes at all. I don't know to what extent > the issue is an > Example: > me : Unitarian > http://en.wikipedia.org/wiki/Tim_Berners-Lee > is a member of the class of > http://en.wikipedia.org/wiki/Category:Unitarian_Universalists > this is a member of the metaclass: > http://en.wikipedia.org/wiki/Category:People_by_religion > this i member of the metametametaclass of ways in whcih people are categorized > http://en.wikipedia.org/wiki/Category:People > What follows here is the weak link. Reference is a section of the library. > "This category is for information typically found in the > reference section of a library: reference works." Now the meta meta > class is regarded as a work? o-oh. > http://en.wikipedia.org/wiki/Category:Reference > it continues, following Category (rdf:type in dbpedia): > http://en.wikipedia.org/wiki/Category:Knowledge > http://en.wikipedia.org/wiki/Category:Information > http://en.wikipedia.org/wiki/Category:Physical_quantity > http://en.wikipedia.org/wiki/Category:Measurement > http://en.wikipedia.org/wiki/Category:Scientific_observation > http://en.wikipedia.org/wiki/Category:Data_collection > http://en.wikipedia.org/wiki/Category:Data_management > http://en.wikipedia.org/wiki/Category:Product_development > http://en.wikipedia.org/wiki/Category:Product_management > http://en.wikipedia.org/wiki/Category:Engineering > http://en.wikipedia.org/wiki/Category:Applied_sciences > http://en.wikipedia.org/wiki/Category:Science > http://en.wikipedia.org/wiki/Category:Knowledge > Ooops! It is cyclic. > The logical relationships are not consistent. i don't know > whether there are a finite number of > categories for which rdfs:class does not work, which could be put > into a stop list. "Reference" would be one. > I wonder whether dbpedia could either find a way of judging which > ones are really rdf:type relationships, or just use something vaguer > for the relationship. > Maybe wikepedia:category would be best as that is what it is in general. > Tim -- Ñ óâàæåíèåì, Leonid mailto:leo@mgn.ru
Received on Sunday, 20 May 2007 19:16:14 UTC