Hugh Glaser wrote:
Hi,
I think Nathan is talking about properties of properties, not instances.
I am, but not in the way you think (afaict).
As a real example, in my Detail RBK/dotAC rendering I have (at least) the
following predicates to look at for names:
(<http://xmlns.com/foaf/0.1/name> <http://www.aktors.org/ontology/portal#full-name>
<http://www.w3.org/2000/01/rdf-schema#label> <http://www.rkbexplorer.com/ontologies/jisc#name>
<http://www.w3.org/2004/02/skos/core#prefLabel> <http://www.w3.org/2004/02/skos/core#altLabel>
<http://rdf.freebase.com/ns/type.object.name>)
I can either use these to gather all the names I can, or use it as an ordered
list to get the one I prefer (if any) - it depends on the display I want to
give.
Or you can use subPropertyOf entailment (rdfs7), when you apply it you'll find
you have an rdfs:label triple for each of the properties you listed, other than
portal#full-name.
So I interpreted Nathan as asking if there was anything that allowed me to say
what the preferred order of predicate choice might be.
This is where the confusion was, if you consider the following graph:
:foo rdfs:label "Michael"@en, "M. Jackson"@en, "Michael Jackson"@en ;
skos:prefLabel "Michael Jackson"@en ;
As humans we know what "prefLabel" means, but a machine doesn't.
Another example:
:foo owl:sameAs </things#foo>, <http://example.org/things/bits#foo> ;
con:preferredURI :foo .
As humans we again know to treat :foo as the canonical/preferred URI for this
thing (just as TimBL has in his foaf). Again, no machine understanding.
Thus I thought if we're going to have a proliferation of preferredXXXX style
properties, it would be good to have a single machine property that explained
this.
So for the two examples above you could have in the ontologies:
rdfs:label x:preferred skos:prefLabel .
owl:sameAs x:preferred con:preferredURI .
Then machines could understand what we do too.
Do I prefer <http://www.w3.org/2000/01/rdf-schema#label> over
<http://www.w3.org/2004/02/skos/core#altLabel> for example (for my particular
application)?
Your dealing with application display preferences here rather than specifying
in descriptions of things that it is known by several values (names,uris) and
this here one is (preferred, canonical) by the resource (or resource owner).
How do I represent that is what I am doing to agents asking (in RDF/OWL of
course)?
And how would a data publisher tell my consumer agent what they think I should
prefer?
The x:preferred approach would handle this at the ontology level, as explained
above - it would capture that when you have multiple values for :a and a single
value for :b, and that :b x:preferred :a, then the value for :b is the
preferred/canonical value out of those specified for :a.
In my case, following Nathan's email, I would have a chain of
<http://www.aktors.org/ontology/portal#full-name> x:preferred
<http://xmlns.com/foaf/0.1/name> .
<http://www.w3.org/2000/01/rdf-schema#label> x:preferred
<http://www.aktors.org/ontology/portal#full-name> .
etc.
Which would be the (meta)metadata about the service I am providing.
I think it may be more a case of capturing this using owl/rif/n3 - supposing
you have the data:
:foo rdfs:label "Michael"@en, "M. Jackson"@en, "Michael Jackson"@en ;
foaf:name "Michael Jackson"@en ;
and in an ontology:
rdfs:label x:preferred skos:prefLabel .
and you have a personal preference that says if a foaf:name and rdfs:label are
present for something, then the foaf:name is the preferred value, then you can
capture this with a rule like:
{ ?t rdfs:label ?l ; foaf:name ?n } => { ?t skos:prefLabel ?n }
Using several rules of this kind you could capture all your preferences, and
your application would universally understand which to display - but over all
properties with multiple values where one is preferred, as :prop1 x:preferred
prop2 . would encode this.
Make sense?
Best, Nathan
However, in some sense rdfs:subPropertyOf might imply this.
Were I loading the data into a store, rather than just doing pure Linked Data
URI resolution, I would be able to assert the rdfs:subPropertyOf relation,
which might be seen to suggest that the most specific property (is that the
right terminology?) is a good one to choose.
I then have the challenge of doing a query that finds that out, of course.
I am guessing that from Nathan's meaning of x:preferred, it would seem that
x:preferred rdfs:subPropertyOf rdfs:subPropertyOf .
By the way, if I only want one preferred property, I can look one of the
properties up in a sameAs store such as sameAs.org to find out what the
suggested canon is (and what the other predicates might be.)
Best
Hugh
On 16 Jul 2012, at 22:28, Tim Berners-Lee <[email protected]> wrote:
Interesting to go meta on this with x:preferred .
What would be the meaning of "preferred" -- "preferred by the object itself or
the owner of the object itself"?
In other words, I wouldn't use it to store in a local store my preferred names
for people, that would be an abuse of the property.
Tim
On 2012-07 -15, at 19:42, Nathan wrote:
Essentially what I'm looking for is something like
foaf:nick x:preferred foaf:preferredNick .
rdfs:label x:preferred foaf:preferredLabel .
owl:sameAs x:preferred x:canonical .
It's nice to have con:preferredURI and skos:prefLabel, but what I'm really
looking for is a way to let machines know that x value is preferred.
Anybody know if such a property exists yet?
Cheers,
Nathan
