AW: [mawg] [rdfs taskforce] action-249: RDFS version of ma-ont availble

Dear Tobias, Chris, Jean-Pierre, all,

I generally agree to Chris‘ comments, and I’d like to add the following:

1. as Chris has mentioned, there are several properties which have type and value, and could be modelled as classes. I think this applies to the following properties: Identifier, title, createDate, policy, copyright, targetAudience, rating
I’m not sure that using subproperties can work for all of them, e.g. how would you deal with the 4 attributes of rating, and would you want define a subproperty for each identifier of copyright or policy?

frameSize (width, height, unit) is now represented as frameWidth, frameHeight – I’m not sure why we should model this different than other complex properties, so I’d suggest to model it as a class with its 3 properties

keyword and genre are defined to be a string OR a URI, the current definition with skos:Concept is more strict as it excludes the string option.

2. Person/Organisation: I agree with Jean-Pierre’s and Chris’ comments, and part of the issues coming fromm mixing two dimensions of specialisation, namely into Person/Organisation and Creator/Contributor/Publisher. According to our ontology document we do not discriminate between persons and organisations, so an Agent specialised into Creator/Contributor/Publisher would be sufficient to represent what we have defined in our ontology document.

3. I agree that a MediaFragment should be a subclass of MediaResource. I’m also not sure whether we need Track as a separate class, as they are MediaFragments, but if we have a separate class, it should be a subclass of MediaFragment.

Best regards,
Werner

Von: public-media-annotation-request@w3.org [mailto:public-media-annotation-request@w3.org] Im Auftrag von Chris Poppe
Gesendet: Freitag, 11. Juni 2010 08:54
An: 'Evain, Jean-Pierre'; 'Tobias Bürger'; johns@postech.ac.kr
Cc: public-media-annotation@w3.org
Betreff: RE: [mawg] [rdfs taskforce] action-249: RDFS version of ma-ont availble

In the RDFS ontology, I assume that Audio and Image, should also be subclassed from MediaResource.

General comments, starting from the Ontology document [1]:

·         Should the ontology more closely represent the “ontology” described in the Ontology document?

·         The ma:identifier property holds both the actual id and a category of the identifier (see [1]).
 So would it make sense to make identifier an ObjectProperty pointing to an Identifier  Class, which has two dataproperties ( id, range: URI and type, range: String)?

·         The same holds for title and all other “subtype properties”. I read somewhere that you want to use subproperties for types of titles. E.g., make mainTitle a subproperty of the title dataproperty?
It would be good to add such a subproperty already to the ontology.

·         I find it strange that Persons and organizations are subclasses of Creators, Publishers, and Contributors. IMO this makes no sense, because this states that all persons are Creators, Publishers and Contributors… I would prefer to include Agent taking Persons, Organizations as subclass (like in FOAF). (Is there a reason for not reusing FOAF classes?).
Additionally, I would make Contributor a subclass of Agent. So if we have a Person Instance Person_0 and add a  MediaResource_0 hasContributor Person_0  it can be deduced that Person_0 is both a person and contributor (the same is possible for organizations).

·         How is the role defined for contributors/creators?

·         When I open the ontology in Protégé, I see the Person classes at different places, is it necessary to explicitly state that Person is a subclass of Thing , or was this generated automatically?

·         How will the different types of dates be defined?

·         Could you give an example of instance data for the SKOS:Concept used for genre/keyword/rating/targetaudience?

·         For the collections, inverse properties would be usefull

·         For the fragments, how about making MediaFragment a subclass from MediaResource?

·         Add a label dataproperty, range:string to the NamedMediaFragment Class

·         Add the technical properties to the correct subclass of MediaResource (e.g., frameWidth and frameHeight for Image and Video, samplingRate for Audio)

·         I think it would be nice to add annotations to the different classes, properties, and so on.

·         Should these tracks be included as separate classes? Are these also MediaResources, or even MediaFragments? The ontologydoc does not include information on the tracks themselves, only on the number ☺
Some comments on Jean-Pierre’s comments I added inline below ([CP])


Kind regards,
Chris



[1]  http://www.w3.org/TR/2010/WD-mediaont-10-20100608/







From: public-media-annotation-request@w3.org [mailto:public-media-annotation-request@w3.org] On Behalf Of Evain, Jean-Pierre
Sent: maandag 7 juni 2010 11:32
To: 'Tobias Bürger'; johns@postech.ac.kr
Cc: public-media-annotation@w3.org
Subject: RE: [mawg] [rdfs taskforce] action-249: RDFS version of ma-ont availble

Hello Tobias,

A few comments:


-          When looking at the ontology in Protégé, datatype like integer appear as classes… That is weird.

[CP] I don’t have this problem, Which version of Protégé are you using?


-          This is why you have what I believe is a wrong use of 'object properties'.  For example, bitrate should be a dataproperty  of media resource instantiated by an integer (not a float ;-)

[CP] (In the version that I see online, bitrate is  a dataproperty)
In fact, the ontology document states that bitrate is a Float, maybe we should also rename this property to averageBitrate as in the ontology document?


-          Language is not a class but an object property linking to a SKOS concept or a data property linking to a string -> the same for e.g. compression, format, genre, keyword, rating and targetAudience


[CP] In the version I have, language is a dataproperty, so I am beginning to think that I am reviewing a revised version?


-          Person should also be a subclass of Actor and probably organisation could also appear where person is.

-          The flattest the better: I would avoid nesting too much things like audio/video, tracks and then audio/video tracks

-          partOfCollection could be replaced by a more generic isMemberOf

-          relation would sound better like isRelatedTo and all Dublin Core relation could be subproperties

-          For the datatype of samplingRate, we often use rationals, which don't exist in RDF -> float?

-          Some properties are functional

-          Some properties are inverse, which I believe needs to be completed by proper object properties

-          Time to think of appropriate inverse properties for more inference

I have put a revised version here: http://www.ebu.ch/metadata/ontologies/W3C_MAWG/ma-ont-rev.rdfs.xml


To be discussed ☺

Regards,

Jean-Pierre

From: public-media-annotation-request@w3.org [mailto:public-media-annotation-request@w3.org] On Behalf Of Tobias Bürger
Sent: jeudi, 3. juin 2010 08:03
To: johns@postech.ac.kr
Cc: public-media-annotation@w3.org
Subject: Re: [mawg] [rdfs taskforce] action-249: RDFS version of ma-ont availble

Hi John,

starting next week is fine - every review is more than welcome!

Thank you in advance!

Best regards,

Tobias

Am 03.06.2010 03:08, schrieb Strassner John Charles:
Hallo Tobias,

I am happy to provide a review of both the RDFS and OWL documents; however, I cannot start the review until next week. I hope that is OK.

regards,
John
--- Original Message ---
From : "Tobias Bürger"<tobias.buerger@salzburgresearch.at><mailto:tobias.buerger@salzburgresearch.at>
To : "public-media-annotation@w3.org"<mailto:public-media-annotation@w3.org><public-media-annotation@w3.org><mailto:public-media-annotation@w3.org>
Date : 2010/06/02 Wednesday PM 5:51:18
Subject : [mawg] [rdfs taskforce] action-249: RDFS version of ma-ont availble

Dear all,

I have now also uploaded the RDFS version of the first implementation of
ma-ont.

You can find it here: http://www.salzburgresearch.at/~tbuerger/ma-ont.rdfs

Browsable version:
http://liris.cnrs.fr/~pchampin/wsgi/t4r/?tu=ontoview.html&r=http%3A//www.w3.org/ns/ma-ont&gu=http%3A//www.salzburgresearch.at/~tbuerger/ma-ont.rdfs


I am still looking for a volunteer to provide a review and to suggest
changes, extensions, etc. for both RDFS and OWL versions of ma-ont. Thanks.

Best regards,

Tobias

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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<mailto:tobias.buerger@salzburgresearch.at>

A-5020 Salzburg | AUSTRIA         http://www.salzburgresearch.at