Re: RE : [mawg] action-249: Ontology Rev. 7 available

  Dear all,

let me step into this discussion.

First of all, I guess the fact that we decided that the Media Ontology 
as it is defined in our document is a flat list of properties should not 
restrict ourselves in building an ontology (using an ontology definition 
language) that models the universe captured by the Media Ontology more 
precisely (meaning with more precise semantics). Having said that, I am 
strongly in favor of defining creator to be a subclass of contributor if 
we think the semantics of this relationship hold. For me a creator of a 
media resource is always a contributor and thus this relationship holds 
in my opinion. The same is true for the other roles (i.e. actor and 
publisher also are some type of contributor).

There was also the issue about Actor. If I recall correctly, then we 
said in one meeting that we would like to have Actor as a class (F2F in 
Vienna). But if the group thinks we should mark it as an extension, we 
can do that.

With respect to some properties/concepts we introduced in addition to 
the core MAWG properties (defined in the document), they do in most 
cases define the relations between concepts defined in our ontology more 
clearly and make them explicit; such as isMadeOf to be able to relate 
tracks to MediaResources. Also we introduced Agents (Persons or 
Organisations) to be able to express who can be creator or contributor 
of a resource. I definitely would keep this. If the group decides to 
remove all of this, then we end up with a flat list of properties again 
(without defining any precise semantics) and this is not what we want at 
this point, I'd say.

Best regards,

Tobias

Am 08.09.2010 17:13, schrieb Evain, Jean-Pierre:
> Dear Werner,
>
> For the choice of the classes, it was the MAWG choice to have actor. And to be consistent actor is a class and not a property.
>
> I wouldn't undermine the MAWG ontology e.g. because mpeg did some wrong ontological assumptions. Look at the questiosn I asked and must be asked to decide if classes are sub-classes and o what. The current classification is natural.
>
> Definitely I beleiev being able to factor queries is clearly and advantage. this is also one of the reasons why we introduced the notion of agent.
>
> Best regards,
>
> Jean-pierre
>
> ________________________________________
> De : Bailer, Werner [werner.bailer@joanneum.at]
> Date d'envoi : mercredi, 8. septembre 2010 16:26
> À : Evain, Jean-Pierre; Tobias Bürger
> Cc : public-media-annotation@w3.org
> Objet : AW: [mawg] action-249: Ontology Rev. 7 available
>
> Dear Jean-Pierre,
>
> then main difference is that there is a class Actor in the ontology, but no corresponding property in our table (meaning property in the sense of  "core property" in our specification, which does not necessarily mean that this is modelled as a property in the ontology). Actor is one of the many possible subtypes of contributor, which we decided not to exhaustively list in our spec.
>
> Concerning the question of contributor and creator, I think it should be as much aligned with our list of core properties as possible, as well as the formats we support in the mapping table. And as far as I see from the mapping tables, some formats have them separate, one uses Creator as the superclass, some make no distinction. So whatever we choose, it will not be perfectly aligned with any of the formats. But I do not see a reason for defining creator as a subclass of contributor, rather for keeping them separate.
>
> Best regards,
> Werner
>
>
> ________________________________________
> Von: Evain, Jean-Pierre [evain@ebu.ch]
> Gesendet: Mittwoch, 08. September 2010 16:02
> An: Bailer, Werner; Tobias Bürger
> Cc: public-media-annotation@w3.org
> Betreff: RE: [mawg] action-249: Ontology Rev. 7 available
>
> By the way I fail to see how the current owl file is different from our property definitions (this without saying that I feel some vagueness in the notions of class vs. Property in your comment - with all due respect Werner ;-)
>
> JP
>
> -----Original Message-----
> From: public-media-annotation-request@w3.org [mailto:public-media-annotation-request@w3.org] On Behalf Of Bailer, Werner
> Sent: mercredi, 8. septembre 2010 15:41
> To: Tobias Bürger
> Cc: public-media-annotation@w3.org
> Subject: AW: [mawg] action-249: Ontology Rev. 7 available
>
> Dear Tobias,
>
> thanks for this draft. I have the following comments:
>
> - As I posted to the list earlier, I wonder why Creator is a subclass of Contributor. In our list of properties they are disjoint, as in some other formats (e.g. EBUCore), in MPEG-7 it's even the other way round (Creator being the superclass): I'm in favour of keeping them separate, as I think it's confusing to model that differently than in our properties definition.
>
> - We should be careful to align the ontology with our list of properties, e.g. Actor is useful as an example, but not defined in our list of properties, thus it should not be included in the official ontology that we publish.
>
> Best regards,
> Werner
>
> ________________________________________
> Von: public-media-annotation-request@w3.org [public-media-annotation-request@w3.org] im Auftrag von Tobias Bürger [tobias.buerger@salzburgresearch.at]
> Gesendet: Mittwoch, 08. September 2010 14:28
> An: public-media-annotation@w3.org
> Betreff: [mawg] action-249: Ontology Rev. 7 available
>
>    Dear all,
>
> after some discussions in the previous week, we made an update to the
> ontology which you can find at
> http://www.salzburgresearch.at/~tbuerger/ma-ont-rev7.owl
>
> What we changed:
> We changed the things to which Pierre-Antoine referred to in his
> comments 1 and 3 in
> http://lists.w3.org/Archives/Public/public-media-annotation/2010Aug/0027.html,
> that is, we fixed the properties with multiple domain declarations
> (e.g., title and locator) and we adapted the Contributor subclass hierarchy.
>
> Furthermore we added a new property isMadeOf to express that a
> MediaResource can be made of Audio - and/or VideoTracks.
>
> I would like to note that we did not change the modelling wrt. to the
> restricted use of some properties (.e.g duration does not apply to
> Images) as both discussed options have their drawbacks in the one or
> other direction (e.g. when introducing new subclasses of MediaResource
> or when adding new properties whose use shall be restricted somehow).
> The same arguments as the ones from Pierre-Antoine against the current
> solutions can be made with his proposal because what, for instance,
>
> ma:Image rdfs:subClassOf ma:MediaResource, [
>       a owl:Restriction ;
>       owl:onProperty ma:duration ;
>       owl:cardinality 0
>     ]
>
> tells us is, that Images are MediaResources which do not have a duration
> property. This gives imho also gives a wrong impression.
>
> I had a discussion internally in my group and without telling them what
> options are being discussed at the moment, most of them favored the
> modelling which we currently have in our version.
> Both aspects lead me to the conclusion that I keep this part of our
> ontology as it is for now. Unless new arguments or majority votes
> against our current modelling pop up :-)
>
> Any feedback is again highly welcome!
>
> @Thierry: If there are no objections you might publish this draft in the
> W3C web space.
>
> Best regards,
>
> Tobias
>
> --
> ================================================================
> Dr. Tobias Bürger         Knowledge and Media Technologies Group
> Salzburg Research                           FON +43.662.2288-415
> Forschungsgesellschaft                      FAX +43.662.2288-222
> Jakob-Haringer-Straße 5/III   tobias.buerger@salzburgresearch.at
> A-5020 Salzburg | AUSTRIA         http://www.salzburgresearch.at

-- 
================================================================
Dr. Tobias Bürger         Knowledge and Media Technologies Group
Salzburg Research                           FON +43.662.2288-415
Forschungsgesellschaft                      FAX +43.662.2288-222
Jakob-Haringer-Straße 5/III   tobias.buerger@salzburgresearch.at
A-5020 Salzburg | AUSTRIA         http://www.salzburgresearch.at

Received on Tuesday, 14 September 2010 10:07:18 UTC