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RE: [mawg] RE: [q] MAWG: Definition of subproperties

From: Bailer, Werner <werner.bailer@joanneum.at>
Date: Fri, 20 Nov 2009 08:37:30 +0100
To: Felix Sasaki <felix.sasaki@fh-potsdam.de>
CC: "Evain, Jean-Pierre" <evain@ebu.ch>, Pierre-Antoine <pierre-antoine.champin@liris.cnrs.fr>, Joakim Söderberg <joakim.soderberg@ericsson.com>, Tobias Bürger <tobias.buerger@sti2.at>, "public-media-annotation@w3.org" <public-media-annotation@w3.org>
Message-ID: <CD9846F872C7874BB4E0FDF2A61EF09F3CDB149B62@RZJC1EX.jr1.local>
Dear Felix,

>> > it is a matter of scope as I said before. If you want a vocabulary in
>> > RDF to which people map, fair enough and I was hopping this was the
>> > original task of the group.
>> I agree with Pierre-Antoine that defining an RDF vocabulary to map to
>> and defining an API to access the properties in this vocabulary are not
>> contradicting goals. In fact, this is how some of the mapping
>> approaches that several people in the group have implemented so far
>> work internally: map to the properties defined in our vocabulary
>> (represented in OWL) and then provide getter functions to access these
>> values. So an implementation getAsRDF() function that gives you the
> source metadata expressed with our vocabulary.
> 
> well, my implementation is XML-based. So I have a very high preference
> to not have to implement RDF-processing to be a conformant
> implementation. So if we create an RDF vocabulary, it should be only
> one serialization of our ontology, and support for it should not be
> mandatory. Do you agree with that?

Yes, I agree. As Doug suggested at the F2F, we can state in the recommendation that the RDF representation is not a mandatory part, however, if someone uses an RDF representation, it needs to conform to the definition in the rec.

> All questions we discuss below about subproperties are IMO independent
> of the question "RDF or not". 

I agree.

Best regards,
Werner

> > More specifically sub properties will either inevitably go further in
> > the direction of one existing vocabulary (then why not adopt) or
> > diverge hence significantly reducing the chances oif mapping in
> profit
> > of a 'nice new vocabulary'.  By the way, by which magic this group in
> > particular would come with the super nice new solution?  All those we
> > are mapping to tried to achieve that goal.
> I absolutely agree that we face these risks. However, as you said, we
> aim at mapping existing formats. If we do not consider subproperties,
> we can only map on a very coarse level, leaving it to the application
> developer to handle the semantics of subproperties coming from
> different formats. In my opinion supporting a defined set of
> subproperties is useful for the following reasons:
> 
> - Allowing users of the API to have well defined semantics of
> subproperties independent of the source format. If the subproperties of
> a property agree in many of the formats, then we do not invent anything
> new and we do not complicate mapping for these formats. If they do not
> match, we have to decide which format to follow and map the others.
> 
> - There are cases where properties are defined on a different
> granularity level. In a format like MPEG-7, we could say we just map to
> creator, and leave the subproperty to a role classification scheme.
> However, ID3 for example has distinct properties for composer, text
> writer, etc., so in such a case we have to make a decision about how to
> map to subproperties of creator.
> 
> - All subproperties that we do not define in our set can still be
> passed on, leaving it to the application developer what to do with it,
> but not losing the information.
> 
> Best regards,
> Werner
> 
> > ________________________________________
> > De : Pierre-Antoine [pierre-antoine.champin@liris.cnrs.fr]
> > Date d'envoi : mercredi, 18. novembre 2009 19:00
> > À : Evain, Jean-Pierre
> > Cc : 'Felix Sasaki'; Joakim Söderberg; Tobias Bürger; public-media-
> > annotation@w3.org
> > Objet : Re: [mawg]  RE: [q] MAWG: Definition of subproperties
> >
> > Jean-Pierre, Felix,
> >
> > If I understand your point, our focus should be on enabling existing
> > formats to map to the API, not on hoping that people will drop those
> > format in favor of RDF with an ad-hoc new vocabulary. And I agree
> with
> > that.
> >
> > However, I don't think that defining an API and defining a language
> are
> > so different tasks as you seem to imply. An API is a vocabulary for a
> > programming language. An ontology is (in the SemWeb world) a
> vocabulary
> > for RDF. We are to focus on the API, granted, and the ontology is
> here
> > only to formally define the mapping. But let's not discard a proposal
> > just because it is about a "vocabulary".
> >
> > I think subproperties would help provide a fine-grain access to the
> > underlying metadata. I think that subproperties should be an optional
> > attribute of our return values. So users could just stick to the
> value
> > (interpreted in the context of the ma: property they retrieved, or
> they
> > could try to make more sense out of the provided sub-property.
> >
> > Whether we should define our own set of subproperty or just reflect
> > those provided by the underlying format... I'm still not sure. Both
> > options have their advantages.
> >
> >   pa
> >
> >
> >
> > Le 18/11/2009 15:28, Evain, Jean-Pierre a écrit :
> > > HI Felix,
> > >
> > >
> > >
> > > That was also my perception.
> > >
> > >
> > >
> > > R, JP
> > >
> > >
> > >
> > > *From:* felix.sasaki@googlemail.com
> > [mailto:felix.sasaki@googlemail.com]
> > > *On Behalf Of *Felix Sasaki
> > > *Sent:* mercredi, 18. novembre 2009 15:20
> > > *To:* Evain, Jean-Pierre
> > > *Cc:* Joakim Söderberg; Tobias Bürger; public-media-
> annotation@w3.org
> > > *Subject:[mawg] * Re: [q] MAWG: Definition of subproperties
> > >
> > >
> > >
> > > Hi Jean-Pierre,
> > >
> > > we are definitely working on a tool to map with a number of
> existing
> > > formats. Note also that all the concrete implementations we have so
> > far
> > > go this route, and the browser scenario proposed by Silvia does
> that
> > > too. The "new" properties are no new vocabulary, but just a means
> to
> > > make clear what the smallest common nominator between existing
> > formats is.
> > >
> > > Best,
> > >
> > > Felix
> > >
> > > 2009/11/18 Evain, Jean-Pierre <evain@ebu.ch <mailto:evain@ebu.ch>>
> > >
> > > Joakim,
> > >
> > > Here we are.  Are we redefining a new Dublin Core ("a nice
> vocabulary
> > > that others would like to use" as you call it) or are we working on
> a
> > > tool to map with a number of existing formats?
> > >
> > > It is a matter of scope.
> > >
> > > In any case, if we want to do the former then we'd better work on
> RDF
> > > and leave those who have used other formats map to it. Then we
> would
> > > really be working on an ontology although archaic for an ontology.
> > >
> > > As I said during the F2F, we would now badly need to know exactly
> > what
> > > we are trying to achieve.
> > >
> > > Regards,
> > >
> > > Jean-pierre
> > >
> > >
> > > -----Original Message-----
> > > From: public-media-annotation-request@w3.org
> > > <mailto:public-media-annotation-request@w3.org>
> > > [mailto:public-media-annotation-request@w3.org
> > > <mailto:public-media-annotation-request@w3.org>] On Behalf Of
> Joakim
> > > Söderberg
> > > Sent: mercredi, 18. novembre 2009 14:57
> > > To: Tobias Bürger
> > > Cc: public-media-annotation@w3.org <mailto:public-media-
> > annotation@w3.org>
> > > Subject:[mawg] RE: [q] MAWG: Definition of subproperties
> > >
> > > Jean-Pierre did not like it because he doesn't believe that there
> > will
> > > be mappings to all sub properties from all formats. Ex. "album
> title"
> > in
> > > TVA, ID3 etc.
> > >
> > > He has a point but I think that if we define a nice vocabulary that
> > > becomes popular, more mappings will follow from several
> contributors.
> > > Which by the way inclines that we should make it possible in the
> > future
> > > to (easily) update the ontology. But I guess that has to do with
> the
> > > implementation.
> > >
> > > /Joakim
> > >
> > > -----Original Message-----
> > > From: Tobias Bürger [mailto:tobias.buerger@sti2.at
> > > <mailto:tobias.buerger@sti2.at>]
> > > Sent: den 18 november 2009 13:57
> > > To: Joakim Söderberg
> > > Subject:[mawg] Re: [q] MAWG: Definition of subproperties
> > >
> > > Hi Joakim,
> > >
> > > I agree, having subproperties is like extending the core set with
> > > qualifying terms for each of the attributes we defined. I think
> that
> > > having subproperties could give us a more precise way to define the
> > > mappings and not to end up in being too generic in parts where most
> > of
> > > the formats we have in scope are more specific.
> > >
> > > I have seen that there were some people that did not like the idea
> of
> > > subproperties @ the F2F. What were their arguments (if you
> remember)?
> > >
> > > Best regards,
> > >
> > > Tobias
> > >
> > > Joakim Söderberg wrote:
> > >> Hi Tobias, thanks for accepting the AP.
> > >>
> > >> I had a look at the properties defined in AMG (All Media Guide;
> see
> > > Video_tables) and EBU (see zip file).
> > >>
> > >> The more I think about the sub-properties the more I think they
> are
> > an
> > > integral part of the Ontology. It's like extending the core set
> with
> > > qualifying terms for each core attribute, or what do you think?
> > >>
> > >>
> > >> All the best
> > >> Joakim
> > >>
> > >> -----Original Message-----
> > >> From: Tobias Bürger [mailto:tobias.buerger@sti2.at
> > > <mailto:tobias.buerger@sti2.at>]
> > >> Sent: den 18 november 2009 08:32
> > >> To: Joakim Söderberg
> > >> Subject:[mawg] [q] MAWG: Definition of subproperties
> > >>
> > >> Hi Joakim,
> > >>
> > >> as you might know I got the action to work on the subproperties
> for
> > > the properties we defined in the ontology. I started to read what
> you
> > > discussed during the F2F and also talked to Florian yesterday to
> > discuss
> > > this.
> > >> I have seen that you have already started on this issue at
> > >> http://www.w3.org/2008/WebVideo/Annotations/wiki/Sub_Types
> > >> I just wanted to ask you which sources you already considered,
> i.e.
> > >> where you looked for possible subproperties? Based on that I can
> > start
> > > of working on the subproperties.
> > >>
> > >> Thanks a lot in advance for your answer!
> > >>
> > >> Best regards,
> > >>
> > >> Tobias
> > >>
> > >> --
> > >> _________________________________________________
> > >> Dr. Tobias Bürger
> > >>
> > >> STI Innsbruck
> > >> University of Innsbruck, Austria
> > >> http://www.sti-innsbruck.at/
> > >>
> > >> tobias.buerger@sti2.at <mailto:tobias.buerger@sti2.at>
> > >> __________________________________________________
> > >>
> > >
> > > --
> > > _________________________________________________
> > > Dr. Tobias Bürger
> > >
> > > STI Innsbruck
> > > University of Innsbruck, Austria
> > > http://www.sti-innsbruck.at/
> > >
> > > tobias.buerger@sti2.at <mailto:tobias.buerger@sti2.at>
> > > __________________________________________________
> > >
> > >
> > >
> > >
> > > -------------------------------------------------------------------
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Received on Friday, 20 November 2009 07:38:39 GMT

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