Swoogle knows how Semantic Web ontologies are used: "
The Dublin Core Metadata
Initiative is updating the RDF expression of DC and might add
range restrictions to some properties. Mikael Nilsson wondered if
we would use the Swoogle
Semantic Web search engine to see what types of values are
being used with DC properties.
This kind of query is just the ticket for Swoogle. Well, almost.
The current web-based interface supports a limited number of query
types. Many more can be asked if you use SQL directly to query
Swoogle’s underlying databases. We don’t want to provide a direct
SQL query service over the main Swoogle database because it’s easy
to ask a query that will take a looooooong time to answer and some
could even crash the database server. We are planning to put up a
second server with a copy of the database and we give Swoogle
Power Users (SPUs) access to it.
We ran a simple SQL query to generate some initial data for
Mikael showing fall of the DC properties. For each one, we list all
of the ranges that values were drawn from and the number of
separate documents and triples for each combination. For
example
Property
|
Range
|
Documents
|
Triples
|
dc:creater |
rdfs:Literal |
32
|
648
|
dc:creator |
rdfs:Literal |
234655
|
2477665
|
dc:creator |
wn:Person |
2714
|
1138250
|
dc:creator |
cc:Agent |
4090
|
6359
|
dc:creator |
foaf:Person |
2281
|
5969
|
dc:creator |
foaf:Agent |
1723
|
3234
|
Notice that the first property in this partial table is an
obvious typo. You can see the complete table as
pdf file or as an excel
spreadsheet.
[Tim Finin, UMBC ebiquity lab]
"
(Via Planet RDF.)