Re: My best practices for Ontology versioning for http://nlp2rdf.org, was Re: Versioning system for ontologies

Hi, I'm not sure I see the issue here.


2013/4/22 Sebastian Hellmann <hellmann@informatik.uni-leipzig.de>

>  Hm, no actually, this issue is quite easy, when it comes to large
> databases.
>
> curl -H "Accept: text/turtle" "http://dbpedia.org/ontology#PopulatedPlace"<http://dbpedia.org/ontology#PopulatedPlace>
> is pretty much the same as:
> curl -H "Accept: text/turtle" "http://dbpedia.org/ontology"<http://dbpedia.org/ontology>
>
But here you are not asking for any instance. You are asking for a document
where the ontology is defined.

>
> So my questions are:
>
> 1. What do you think is the expected output of http://dbpedia.org/ontology? 300 million triples as turtle?
>
No. You would see the description of the ontology. In DB-pedia they haven't
done such redirection because
they are exposing both terms and classes with Pubby. But note that when you
look for a term, no instances
are returned.

2. How do you query all instances of type db-ont:PopulatedPlace via Linked
> Data ?
>
Via a SPARQL query:
select ?instance where{
?instance a db-ont:PopulatedPlace.
}
If you don't want all the instances, then add a "LIMIT". That is why they
have a public endpoint, right?

Another example. The recent PROV-O Ontology (with namespace URI
http://www.w3.org/ns/prov#).
If I have an endpoint with many prov:Entities published and I want them, I
can perform a query
as the one I did above. If I want to see the documentation of the term,
then I would ask for
http://www.w3.org/ns/prov#Entity and I would be redirected to it.
Doing an accept request for turtle to an ontology term would return the owl
file of the ontology,
not the instances of that term.

Best,
Daniel

>
> q.e.d from my point of view, as you wouldn't get around these practical
> problems.
>
> -- Sebastian
>
> Am 22.04.2013 11:50, schrieb Daniel Garijo:
>
>  Dear Sebastian,
>  This statement:
> "When you publish ontologies without data, you can use '#' . However, if
> you want to query instances via Linked Data in a database, you have to use
> '/' as DBpedia does for classes:
> http://dbpedia.org/ontology/PopulatedPlace"
>
> is not correct. You can use "#" to query instances via Linked Data
> databases. That is just the URI of the type. In fact if DBpedia had chosen
>
> "http://dbpedia.org/ontology#PopulatedPlace<http://dbpedia.org/ontology/PopulatedPlace>"
> instead of its current URI it would still be fine. It doesn't affect the
> query.
>
> I'm not going to enter in the debate of "# vs /", but normally it is a
> design decission that has to do more with the size of vocabularies than the
> instances.
>
> Best,
> Daniel
>
>
> 2013/4/22 Sebastian Hellmann <hellmann@informatik.uni-leipzig.de>
>
>>  Dear all,
>>
>> personally, I have been working on this for quite a while and for me the
>> best and easiest way is as documented here:
>> https://github.com/NLP2RDF/persistence.uni-leipzig.org#readme
>>
>> They are simple and effective and I couldn't imagine anything more.
>>
>> Note that I have also secured persistent hosting for the URIs (also an
>> important point).
>> Feedback welcome, of course.
>>
>> All the best,
>> Sebastian
>> Ontology: http://persistence.uni-leipzig.org/nlp2rdf/ontologies/nif-core#
>>  # vs /
>>
>> When you publish ontologies without data, you can use '#' . However, if
>> you want to query instances via Linked Data in a database, you have to use
>> '/' as DBpedia does for classes:
>> http://dbpedia.org/ontology/PopulatedPlace
>>  <https://github.com/NLP2RDF/persistence.uni-leipzig.org#workflow>
>> Workflow
>>
>>    1. I edit the ontologies in turtle syntax with the Geany text editor
>>    (or a Turtle editor
>>    http://blog.aksw.org/2013/xturtle-turtle-editing-the-eclipse-way ),
>>    This allows me to make developers comments using "#" directly in the
>>    source, see e.g. nlp2rdf/ontologies/nif-core.ttl
>>    2. When I am finished I use rapper (
>>    http://librdf.org/raptor/rapper.html) to convert it to rdfxml (
>>    nlp2rdf/ontologies/nif-core.owl )
>>    3. I am versioning the ontologies in a folder with the version
>>    number, e.g. version-1.0 If somebody wants to find old ontologies, she can
>>    find them in the GitHub repository, which is linked from the ontology. I
>>    assume this is not often required, but it is nice to keep old versions. The
>>    old versions should be linked to in the comment of the ontology, see the
>>    header of nif-core.ttl
>>    4. Then I use git push to push the changes to our server
>>    5. (not yet) I use a simple OWL2HTML generator, e.g.
>>    https://github.com/specgen/specgen
>>    6. add yourself to http://prefix.cc, see e.g. http://prefix.cc/nif
>>    7. The versions are switched and published by these .htaccess rules,
>>    e.g.
>>    RewriteRule .(owl|rdf|html|ttl|nt|txt|md)$ - [L]
>>    # (in progress) RewriteCond %{HTTP_ACCEPT} text/html
>>    # (in progress) RewriteRule ^nif-core$
>>    /nlp2rdf/ontologies/nif-core/version-1.0/nif-core.html [R=303,L]
>>
>>    RewriteCond %{HTTP_ACCEPT} application/rdf+xml
>>    RewriteRule ^nif-core$
>>    /nlp2rdf/ontologies/nif-core/version-1.0/nif-core.owl [R=303,L]
>>
>>    RewriteRule ^nif-core$
>>    /nlp2rdf/ontologies/nif-core/version-1.0/nif-core.ttl [R=303,L]
>>
>>
>>
>>
>>
>>
>> Am 19.04.2013 16:05, schrieb Prateek:
>>
>>  Hello all,
>>
>>  I am trying to identify a system which will provide versioning and
>> revision control capabilities specifically for ontologies. Does anyone have
>> any experience and idea about which systems can help out or if systems like
>> SVN, CVS can do the job?
>>
>>  Regards
>>
>>  Prateek
>>
>>  --
>>
>> - - - - - - - - - - - - - - - - - - -
>> Prateek Jain, Ph. D.
>> RSM
>> IBM T.J. Watson Research Center
>> 1101 Kitchawan Road, 37-244
>> Yorktown Heights, NY 10598
>> Linkedin: http://www.linkedin.com/in/prateekj
>>
>>
>>
>> --
>> Dipl. Inf. Sebastian Hellmann
>> Department of Computer Science, University of Leipzig
>> Projects: http://nlp2rdf.org , http://linguistics.okfn.org ,
>> http://dbpedia.org/Wiktionary , http://dbpedia.org
>> Homepage: http://bis.informatik.uni-leipzig.de/SebastianHellmann
>> Research Group: http://aksw.org
>>
>
>
>
> --
> Dipl. Inf. Sebastian Hellmann
> Department of Computer Science, University of Leipzig
> Projects: http://nlp2rdf.org , http://linguistics.okfn.org ,
> http://dbpedia.org/Wiktionary , http://dbpedia.org
> Homepage: http://bis.informatik.uni-leipzig.de/SebastianHellmann
> Research Group: http://aksw.org
>