On Wednesday 08 March 2006 17:58, Marco Brandizi wrote:
> Hi all,
> I've just discovered the Semantic Media Wiki project and it looks very
> interesting (cool and fun! ;-) ).
Sure! -- that's why we do it ;-)
> I'd like to use it in a project of my own, but probably I would need to
> write some changes/extensions. Isn't there some documentation about?
> Even something minimal, such as a guideline about where to start looking
> the code would be helpful however.
There is no such documentation yet, but I am happy to help out.=20
> First things I have in mind are:
> - Support for reading RDF from external sources (via URI or alike).=20
What does it mean to "read RDF" with the wiki? Do you want to somehow "impo=
data? Denny and I are currently about to implement an extension that import=
external OWL/RDF specifications and that allows the wiki to produce data fo=
these ontologies (i.e. using the URIs of the imported ontology instead of t=
wiki URIs). Is this similiar to what you had in mind?
> SPARQL queries like: "find the statements having this page as subject"
> would be interesting
This can already be done with the Special:SearchTriple. Just enter the subj=
page and leave the other fields empty. This does of course not use SPARQL.
SPARQL support is currently being implemented as an external service. This=
does not mean that SPARQL might not be run on the same server -- we just=20
architecturally separate the triplestore+SPARQL from the core wiki.
The reason is that we want to have the ability to run various SPARQL engine=
in parallel in order to find out whether one or more of them shall be=20
eventually integrated into MediaWiki. There is no best triplestore or SPARQ=
engine at the moment, so that will create some direct competition. Also,=20
WikiMedia foundation does not run Java for lack of free implementations. So=
we offer the possibility to still apply Java-triplestores to Wikipedia data=
by running them on external servers.
Anyway, a public demo for a first working SPARQL endpoint will be enabled=20
> - Support for triple stores / RDF frameworks like Jena
This relates to the previous answer. We view SPARQL-support and=20
tripestore-support as mostly synonymous (we do not plan to implement our ow=
SPARQL-engine). We are also about to provide the necessary infrastructure f=
external triplestores to stay in sync with the RDF that is represented by t=
> - Support for adapting rich ontologies that could be derived (or
> similarly adapted) as extensions of current (sincerely) basic
> specification of Categories/Typed Links/Attributes.=20
We will soon support in-wiki markup for role hierarchies, transitive and=20
symmetric roles, and maybe for basic domain and range restrictions, but the=
is no intention so far to provide more complex DL-style statements (i.e. no=
disjunctions, arbitrary existential or universal quantifiers, negations).
It is still an open problem of whether one can edit a complex ontology in a=
distributed collaborative sense (related problem: how to edit an ontology i=
a modular fashion?). The problem is that rich languages such as OWL are=20
inherently non-local: you make a statement in one article, and, combined wi=
a couple of thousand other articles, this makes the whole ontology logicall=
inconsistent. But you cannot easily restrict your attention to a reasonably=
small part of the ontology. So you would always have the whole ontological=
content of your wiki in mind, and thus the distributed environment might be=
problematic for ontology engineering.
Denny and I are currently working on a partial solution for this, which all=
you to work against a fixed background ontology, that cannot be changed in=
> Probably this would =20
> require addition to markup syntax=20
Yes. But one should first decide which language one actually wants to suppo=
in the wiki.=20
> and hence some browsing interface to=20
> select a category or a link type would be useful too.
Yes, this would be nice. We have some ideas, but nothing concrete yet.=20
OK, now lets sum up what features are currently implemented by us, where we=
could use some help, and where nobody is actually working on:
=3D=3D Stuff that we currently work on =3D=3D
* External triplestore and SPARQL service: will be done by us; expected unt=
end of March.
* A smart synchronization API for keeping external triplestores in synch wi=
little network traffic: currently there is only the RDF export (which still=
needs completion), but for small wikis no further optimization is needed. I=
the long run, we have some plans on how to make the synchronization more=20
* Importing parts of external ontologies, creating new articles for their=20
vocabulary, and exporting RDF that uses external URIs: done by Denny and me=
until end of March.
* Inline SPARQL queries for the wiki: done by a new developer who will=20
probably join our team soon.
=3D=3D Stuff that we would be interested in =3D=3D
* User interface support for simplifying semantic annotation. It would be n=
if we could suggest relations or categories for articles. Any ideas?
* SPARQL UIs. We will build online services for executing SPARQL queries. B=
how can an average user enter such a query? We will provide some solutions,=
but the more (easy-to-use) search interfaces the better.
=3D=3D Stuff that we are not focussing on =3D=3D
* Rich ontology language editing inside the wiki. Many unsolved problems he=
Not suitable for Wikipedia, for reasons of scale (reasoning in OWL-Lite is=
already ExpTime ...) and since most people don't understand it.
Just tell us what you would like to do, and I will send you some hints on h=
to approach the code (and also which parts of the code will be fundamentall=
changing in the next week ;-).
> Thanks in advance for the help.
Institute AIFB, University of Karlsruhe, D-76128 Karlsruhe
mak@... phone +49 (0)721 608 7362
http://www.aifb.uni-karlsruhe.de/WBS/ fax +49 (0)721 693 717