[OGDev] What are people working on?

[Tom Heath]

Hi Kake,

Glad it works. You're not wrong, the output is pretty dull isn't it ;)
The issue is this, which I'll hopefully be able to explain
coherently...

URIs
-------

The URI that you plugged in is the URI of a "wiki entry about Angel",
SE16 4NB, not the URI of the thing itself. As a result the browser
only outputs data about the page, not about Angel, SE16 4NB. To see
that, you need to look at the URI
<http://london.randomness.org.uk/wiki.cgi?id=Angel%2C_SE16_4NB;format=rdf#obj>
in Disco:
<http://www4.wiwiss.fu-berlin.de/rdf_browser/?browse_uri=http%3A%2F%2Flondon.randomness.org.uk%2Fwiki.cgi%3Fid%3DAngel%252C_SE16_4NB%3Bformat%3Drdf%23obj>
or <http://tinyurl.com/28pt4k>. Hopefully we'd all agree this is a lot
more interesting :)

One of the things that confuses this issue IMO is the Guides use of
hash URIs, i.e. tagging  #obj on to the end of the URI of a page about
something, to make a URI of the thing itself. It's not a particularly
pretty/ideal pattern to follow in an RDF world. Obviously it's grown
up organically and we're dependent on many other modules, but ideally
we'd use a URI pattern that went something like:
http://wherever.openguides.org/thing-name-locale/
to identify things in the guide, with pages of information about the
things being at
http://wherever.openguides.org/thing-name-locale/about

Revyu follows this sort of pattern. Look up the URI
<http://revyu.com/things/far-from-the-madding-crowd-oxford>
in your browser, and you won't be returned the pub itself, but instead
be redirected to a page with information about it. Replace the /html
you'll likely get in the URL with /rdf for an RDF version. I'm
guessing this isn't really very feasible for the OpenGuides right now,
although liberal use of Apache Rewrite rules might get us a lot of the
way. That aside, in the meantime we can concentrate on linking up the
data in a more interesting way.

Linking within OG
-------------------------

First off, one thing that would help would be to make a link between
the <uriofpageaboutathing> and the <uriofthingitself>. This is lacking
at the moment as far as I can tell, hence the lack of links from
<http://tinyurl.com/ynwxze> to <http://tinyurl.com/28pt4k>. The
foaf:primaryTopic property should be sufficient for this.

The next job is to fix some links in the RDF describing the thing. For example,
<http://london.randomness.org.uk/wiki.cgi?id=Angel%2C_SE16_4NB;format=rdf#obj>
is apparently foaf:based_near
<http://london.randomness.org.uk/wiki.cgi?id=Angel%2C_SE16_4NB;format=rdf#Rotherhithe>
Now, this may not be incorrect, but there is very little info about
Rotherhithe at that URI. Instead we should be saying ...
foaf:based_near
<http://london.randomness.org.uk/wiki.cgi?id=Locale_Rotherhithe;format=rdf>
That RDF file should then ideally contain lat/lon data about
Rotherhithe, and links to all the things located in that locale. The
same issue affects "bob"; rather than just linking to
<somenodename;format=rdf#bob>, it would be great to identify Bob with
a URI, <http://wherever.openguides.org/contributors/bob/> perhaps; an
easy win in the meantime would be to link (with rdfs:seeAlso I guess)
to <http://london.randomness.org.uk/wiki.cgi?action=rc;format=rss;username=bob;items=10>,
which at least starts to link up some of Bob's different entries, even
if not in a very semantically rich way.

After that, we could get on to making links to the Categories that a
thing is within, using the "find all things within x metres of this"
to create some nice rdfs:seeAlso links (or even better, more
foaf:based_near links), and things like that.

Linking outside OG
----------------------------

It would also be very cool to look at linking to other datasets, like
you say. Revyu.com has a SPARQL endpoint against which you can do
remote queries. So it would be relatively easy to do a query saying
"give me all the reviews of things that have rdfs:seeAlso links to
this particular page on the OpenGuides". We could then say that
<thingonrevyu> owl:sameAs <thinginopenguide>, which would give us more
links in browsers. It wouldn't catch all relevant things, as we can't
assume that all reviewers in Revyu will link to relevant pages on the
OpenGuides, but it would be a good start while we development more
sophisticated location and/or string matching-based techniques.

Integration of the OpenGuides with GeoNames would also be a very cool
and very easy win. For example, the URI
<http://sws.geonames.org/2639091/> identifies Rotherhithe, so with a
bit of lat/lon-based validation it would be pretty easy to
autogenerate these links for all Locales in all OpenGuides.
Rotherhithe is described in RDF at
<http://sws.geonames.org/2639091/about.rdf>. The GeoNames guys are
very approachable, so there could be good opportunities for hookups
with the OpenGuides in general.

OK, this emails mammoth, so I'll stop now.

HTH :) I can't promise to contribute code, but happy to advise on
stuff like this,

Tom.

PS. If anyone else on this list is really into this stuff, then the
Linking Open Data project
<http://esw.w3.org/topic/SweoIG/TaskForces/CommunityProjects/LinkingOpenData>
is doing some cool stuff in this space. OpenGuides is already listed
under datasets.



On 15/03/07, Kake L Pugh <kake at earth.li> wrote:
> On Thu 15 Mar 2007, Kake L Pugh <kake at earth.li> wrote:
> > OK, so I looked at an OpenGuides page in it:
> >   http://www4.wiwiss.fu-berlin.de/rdf_browser/?browse_uri=http%3A%2F%2Flondon.randomness.org.uk%2Fwiki.cgi%3Fid%3DAngel%252C_SE16_4NB%3Bformat%3Drdf
> >
> > aka
> >   http://tinyurl.com/ynwxze
> >
> > It isn't very exciting!
>
> Also, the Contributor looks wrong.  How can we get that to point to
> actual-Bob, rather than just a random URI with "bob" in it?
>
> Kake
>
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