> >You can get an idea of the properties used for a particular kind of resource >by following these steps: > >1. Find the class(es) used in DBpedia of that kind of thing. For example, if >you look at a couple of persons, you will find that they usually have the >classes yago:Person100007846 and foaf:Person. Classes in DBpedia are >quite inconsistent, so this is not an easy task.
I've used the two you give: this gives two sets with a large degree of
overlap and not that many new cases for the second class (foaf:Person).
I suspect it be a case of diminishing returns to hunt for any more
classes used to identify people.
>2. Use a SPARQL query like this to find the properties used for any
>particular class:
>
>SELECT DISTINCT ?p
>WHERE {
>?s ?p ?o .
>?s rdf:type <http://dbpedia.org/class/yago/Person100007846> .
>}
>
>You can run the query at http://dbpedia.org/snorql .
Done that. I found (by asking for an ordered result set) that these
queries returned more than the allowed number of hits, so I added regex
filters looking for:
born
birth
died
death
place
date
and copied the resulting XML into a single document. I then sorted
this, stripped out duplicates (e.g. placeOfDeath would be found by two
of these searches), and hand-crafted the attached XML document, which
attempts to group concepts together.
>3. Use a SPARQL query like this to find out how often a particular property
>is used (to see if it's worth spending time on it):
>
>SELECT COUNT(*) WHERE { ?s dbpedia2:dateOfBirth ?o . }
This establishes that the "obvious" ones vastly outnumber the oddities.
>4. Find example triples that use a particular property (to see *how* it's
>used,
>and if it's indeed interchangeable with another property):
>
>SELECT ?s ?o WHERE { ?s dbpedia2:dateOfBirth ?o . }
This is a bit depressing, I must say ... Still, I suppose you can still
query the ones which aren't total cabbage.
>The end result of this process could be triples like this:
>
>dbpedia2:dateOfBirth owl:equivalentProperty dbpedia2:birthdate .
I assume that you would want there to be strict equivalence between the
properties thus linked? I'm assuming so, in which case the number of
equivalences will be quite small.
There are part/whole type relationships between some of them, e.g.
monthofbirth and dateofbirth
cityofbirth and placeofbirth
Can this type of relationship between properties be [usefully]
expressed?
Final question (for now): there are for example seven variants on
"birthDate". Do I need six owl:equivalentProperty statements or 21?
Richard
person-class-groups.xml
Description: person-class-groups.xml
-- Richard Light XML/XSLT and Museum Information Consultancy [EMAIL PROTECTED]
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