<...trimming reply list...>
On 17 Nov 2008, at 23:31, Chris Bizer wrote:
But what does this mean for WEB ontology languages?
Looking at the current discussion, I feel reassured that if you want
to do
WEB stuff, you should not move beyond RDFS, even aim lower and only
use a
subset of RDFS (basically only rdf:type, rdfs:subClassOf and
rdfs:subPropertyOf) plus owl:SameAs. Anything beyond this seems to
impose
too tight restrictions, seems to be too complicated even for people
with
fair Semantic Web knowledge, and seems to break immediately when
people
start to set links between different schemata/ontologies.
Hmm. My sympathies are in this direction, having had unhappy
experiences in the past (akt:Person was very restrictive, IIRC).
However I don't think your conclusion is quite right.
Firstly sameAs has the nasty habit of infecting your data with
somebody else's cruft. In a web context it seems more useful in
conclusions than in premises. seeAlso inverse functional, and some of
the things in OWL 2.
Secondly it's worth revisiting OWL's allValuesFrom, which gives you
the benefit of rdfs:range (to describe data structure) but in a more
limited way. For example it could allow the range of dc:contributor to
be foaf:Person when used with foaf:Documents, but not infect other
uses of the property.
Thirdly hasValue is pleasingly structural. Being able to determine
types not because they have been stated, but because of the features
of the data, has its virtues on the web.
Damian
