Hugh Glaser wrote:
OK Kingsley, it's done (or rather I hope it is!).
Interestingly we never really viewed the html as a web page, it was always a
way of looking at the RDF, in the same sort of way that we might use tabulator.
We would be quite happy to withdraw the html pages altogether.
But for the moment it now has the rel links (and you have encouraged us to do
it earlier rather than later!).
By the way, I couldn't get your issues URI to work, whatever I did.
Best
Hugh
Hugh,
Yes, it's done as exemplified by this browser session URI:
http://demo.openlinksw.com/rdfbrowser2/?uri%5B%5D=http%3A%2F%2Fos.rkbexplorer.com%2Fdescription%2Fosr7000000000017765&;
HTML as Link to RDF Data Sources is a big thing :-) It's an area
typically overlooked (inadvertently most of the time). As part of LOD we
need to emphasize best practices for publishing HTML that exposes
associations with RDF data sources :-) DBpedia's HTML pages have
maintained this linkage from the get-go. Also note, Chris Bizer and
Richard Cyganiak have both been beating this drum for a very long time.
Methinks, that the unobtrusive manifestation of the "Linked Data Web"
depends highly on the linkage between HTML and RDF information
resources. This is why I am ensuring that our user agents are able to
make a best effort to discern the following from HTML pages:
1. What the page is about (Subject matter and Named Entity wise)
2. What Data Sources the page is associated with (as seeAlso)
3. Alternative representations of the page (as in "alternate"
representations)
Increasingly we sniff out the following in (X)HTML information resources:
1. <link rel="[appropriate-predicate]" .../>
2. RDFa (in your case <span/> usage around your table columns would do fine)
3. GRDDL
4. Plain Old Semantic HTML (POSH)
And then depending on the RDF we get, we might perform additional
processing using services such as UMBEL, DBpedia, OpenCalais as part of
the journey towards high context fidelity "Linked Data Spaces" presented
to the Web Users.
BTW - We now have a signed version of the OpenLink Data Explorer plugin
for Firefox <https://addons.mozilla.org/en-US/firefox/addon/8062>. Thus,
if you install and you use the "View | Linked Data Sources" (main menu
or context menu) option when viewing
<http://os.rkbexplorer.com/description/osr7000000000017765>, you will
also see a live example of HTML's utility as vehicle of Linked Data
discovery.
Links:
1. http://ode.openlinksw.com/ - OpenLink Data Explorer Home page (here
you can find What, Why, and How information)
Kingsley
On 13/07/2008 18:56, "Kingsley Idehen" <[EMAIL PROTECTED]> wrote:
Afraz Jaffri wrote:
Sorry, the link i gave was to the HTML description,the URI of the
resource is
http://os.rkbexplorer.com/id/osr7000000000017765
then:
[EMAIL PROTECTED] ~]$ curl -I -H "Accept: application/rdf+xml" http://os.
rkbexplorer.com/id/osr7000000000017765
HTTP/1.1 303 See Other
Date: Sun, 13 Jul 2008 10:44:10 GMT
Server: Apache/2.0.52 (Red Hat)
X-Powered-By: PHP/4.3.9
Location: /data/osr7000000000017765
Connection: close
Content-Type: text/html; charset=UTF-8
Afraz.
Afraz,
Yes, but it is also good practice to link the HTML description with the
RDF representation of the description. This enables the RDF discovery to
start from the HTML description.
This is all that is required:
<link rel="alternate" type="application/rdf+xml"
href="http://os.rkbexplorer.com/data/osr7000000000017765"; />
Of course you can also use RDFa to similar effect by making a seeAlso claim.
Kingsley
Afraz Jaffri wrote:
We are pleased to announce a Linked Data site for the Ordnance
Survey,
available at:
http://os.rkbexplorer.com
with links from over 8000 URIs to Geonames URIs. Take 'Hampshire'
as
an example:
Afraz,
http://os.rkbexplorer.com/description/osr7000000000017765
kidehen$ curl -I -H "Accept: application/rdf+xml"
http://os.rkbexplorer.com/description/osr7000000000017765
HTTP/1.1 406 Not Acceptable
Date: Sat, 12 Jul 2008 20:31:35 GMT
Server: Apache/2.0.52 (Red Hat)
X-Powered-By: PHP/4.3.9
Content-Type: text/html; charset=UTF-8
Connection: close
Why no 303 or use of <link rel="[relavant-predicate]" .../> so that
User Agents can locate <http://os.rkbexplorer.
com/data/osr7000000000017765> .
My issues are summarized here:
http://demo.openlinksw.com/rdfbrowser2/?uri%5B%5D=http%3A%2F%2Fos.
rkbexplorer.com%2Fdescription%2Fosr7000000000017765&uri%5B%5D=http%3A%
2F%2Fos.rkbexplorer.com%2Fdata%2Fosr7000000000017765&
Kingsley
It might also be the right time, with all the owl:sameAs
discussion,
to practically demonstrate how our coreference system works. In the
above example the link created is between 'Hampshire the county'
from
the OS and 'Hampshire the second order administrative division'
from
Geonames. We do not know if these two entities are exactly the
same,
so instead of using owl:sameAs we use our own coref:duplicate
predicate.
One of the features of our system is that knowledge about
coreference
is separated from the knowledge of the actual entity. In the RDF
for
the above URI at http://os.rkbexplorer.com/data/osr7000000000017765
you
will find:
<coref:coreferenceData rdf:resource="http://os.rkbexplorer.
com/crs/osr7000000000017765"/>
Resolving this URI will give you a 'bundle' containing the
duplicates:
<coref:Bundle>
<coref:canon rdf:resource="http://os.rkbexplorer.
com/id/osr7000000000017765"/>
<coref:duplicate rdf:resource="http://os.rkbexplorer.
com/id/osr7000000000017765" />
<coref:duplicate rdf:resource="http://sws.geonames.org/2647554/";
/>
<coref:lastUpdated>2008-07-10 11:39:44</coref:lastUpdated>
</coref:Bundle>
As you can see one URI is chosen as the canonical URI to use. The
separation of coreference means, to a limited extent, that the
context
of duplication can be preserved. If I wanted to say that under some
other context there were other URIs that were deemed to be the same
then I can simply create another bundle with another <coref:
coreferenceData> predicate in the RDF for the entity. Of course, the
question of how to show the context is yet to be solved...
There may be some errors in the equivalences. All feedback is
greatfully received :)
In relation to another question about how owl:sameAs is currently
being used, there are some examples in our LDOW paper:
http://eprints.ecs.soton.ac.uk/15181/
in particular http://dbpedia.org/resource/Welsh and http://dbpedia.
org/resource/Lilac
Regards,
Afraz
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
On
Behalf Of Harry Halpin
Sent: 09 July 2008 10:55
To: Hugh Glaser
Cc: Bijan Parsia; Peter Ansell; semantic-web at W3C; [EMAIL PROTECTED]
org
Subject: Re: How do you deprecate URIs? Re: OWL-DL and linked data
Hugh Glaser wrote:
Thanks guys, a really interesting and important discussion.
However, after the last couple of postings I have the feeling I
may
agree
with both of you.
Is that possible?
Bijan et. al. are right about the semantics of owl:sameAs, but as
I've
said before, I think that something weaker needs to be coined
("lod:equivalentTo") that states that two URIs refer to the same
thing
but that any semantic entailments *may* not hold (i.e. user
beware).
That's a dangerous thing, I agree, but it seems to be what the
Linked
Data community needs and what's happening organically in the wild
with
the (ab)use of owl:sameAs.
Hugh
__________________________________________________________
Free games for a wet weekend - http://www.tiscali.co.uk/play
__________________________________________________________
__________________________________________________________
Free games for a wet weekend - http://www.tiscali.co.uk/play
__________________________________________________________
--
Regards,
Kingsley Idehen Weblog: http://www.openlinksw.com/blog/~kidehen
President & CEO
OpenLink Software Web: http://www.openlinksw.com
--
Regards,
Kingsley Idehen Weblog: http://www.openlinksw.com/blog/~kidehen
President & CEO
OpenLink Software Web: http://www.openlinksw.com
