Re: RE : ma-ont RDF latest version

Hi Tobias,

On Nov 17, 2010, at 19:02 , Tobias Bürger wrote:

> Dear Ivan,
> 
> thanks a lot for your valuable feedback!
> 
> Let me make some comments below. In addition you might also want to inspect the new version of the ontology; see http://lists.w3.org/Archives/Public/public-media-annotation/2010Nov/0100.html
> 
> Am 15.11.2010 11:59, schrieb Ivan Herman:
>> Thierry et al,
>> 
>> first of all, thank you for having made this step forward. Unfortunately, I still have comments and, well, critiques on what is in the editor's draft. Overall, the document looks like the RDF/OWL formalism is put into the document very much as an afterthought, without making clear connections to the core text. Which makes it still very difficult to use the specification.
> What we made last week is a table stating the relation between the properties defined in the editor's draft and the OWL implementation of the ontology (for each element). It has been sent around in this mail: http://lists.w3.org/Archives/Public/public-media-annotation/2010Nov/0094.html

Ah. Of course I would have to see how this table fits into the LC document, but this is indeed the type of things I was looking for. Thank you.


>> Some examples may make my concern clearer.
>> 
>> I am looking at section 5.1.2 which, I expect, gives me the list of properties that I can use in my RDF annotation. First of all, I am not sure what the type description means. The way I make sense out of it for a complex type, in RDF terms, is that I have to create a blank node which may have additional attributes. Ie, is it true that, say, I can/should do something like:
>> 
>> <...>  ma:contributor [
>>    identifier<URI>   ; # or a string
>>    role "SOMESTRING" ; # this is optional
>> ] .
>> 
>> using an entry in the table of 5.1.3. This may makes sense, but it is not clear from the text. For example, in what namespace is 'identifier' and 'role'? Is this really the way the specification has to be translated into RDF?
>> 
>> Well, I would expect having a specification for a ma:contributor in the OWL spec to look it up in the ontology. Hm. There is _no_ entry for #contributor! There is a #contributorIs though, so maybe that is the one and there is mismatch between the two parts of the text; that is fine, you guys will check that. So let us go for #contributorIs, it says its range is #Contributor. Ok, let us go there, maybe it says something about identifier and role. But it does not. And, of course it does not because an OWL ontology's owl:Restriction does not define a constraint on classes, just licenses to infer. So I would look for something like #role, but that is not there either... And then I give up and look for a different ontology for my application.
> You will now get much more information on this from the table mentioned but also from the ontology as such which contains a lot more documentations for its elements than earlier versions.

Great. I am looking forward having a look at the next editors' draft when it is available!

>> I hope you get what I say. The core text should make it very clear how that ontology is to be used by and for RDF, what the 'type definition' means in 5.1.2 and other places, how should I, mentally, translate what is in the tables for a real annotation using RDF. At the moment it does not. More examples would be really useful, b.t.w....
> 
> We will in the next days provide an extensive example on how to use the ontology. Further we are aiming to provide examples on how to use the ontology based on metadata samples from the different formats which we identified in the document. The purpose of this is to validate the ontology (and the mappings).
>> I also have some comments on the ontology itself
>> 
>> - Personally, I would prefer to have the OWL ontology in Turtle, too. Mainly for humans it is much more readable. But that is an editorial choice
> The turtle version will come; also a seperate page (behind the URI of the namespace) with more extensive documentation.

Great!

>> - The starting comment includes
>> 
>>     <song1.mp3>  ma:hasGenre [ rdfs:label "Blues" ] .
>> 
>> which means the overall RDF/XML file invalid in XML:-(
> Hhmm. Translating it to RDF/XML gives me
> 
> <?xml version="1.0"?>
> <rdf:RDF xmlns:rdfs="http://..." xmlns:ma="http://..." xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
> <rdf:Description rdf:about="song1.mp3">
> <ma:hasGenre rdfs:label="Blues" />
> </rdf:Description>
> </rdf:RDF>
> 
> But maybe I did not get your point.

Ah, my comment is moot by now, looking at the new version of the OWL file. It now says, as part of the rdfs:comment

&lt;song1.mp3&gt; ma:hasGenre [ rdfs:label &quot;Blues&quot; ] .

which is then valid XML! 


>> - the datatype specifications are all in
>> 
>>   <rdfs:range rdf:resource="string"/>
>> 
>> but that is incorrect, the resource attribute should have the full XSD URI as a value (one of the features that would keep the specification much more readable in Turtle...)
> Not every datatype property has range String. Again, maybe I do not get your point here as well.

Again, this is moot with the newer version of the OWL file. It now says, e.g.,

<owl:DatatypeProperty rdf:about="#alternativeTitle">
...

 <rdfs:range rdf:resource="&xsd;string"/>
...
</owl:DatatypeProperty>

which is correct. It was "string" in the previous version on the editors' draft, which was incorrect...


>> - I would probably check whether the ontology remains in a profile of OWL, maybe OWL RL. In the application domain of this ontology, close to the RDF world of annotation, it may be very useful to make that sure. If there are features that would push the ontology out of RL, I would probably think through whether that is really necessary, ie, whether the inferences that can be drawn from that part of the ontology are really important and useful in practice...
> We will check if the ontology falls into the OWL RL profile.
>> I hope this helps
> Definitely, thanks a lot!


I am happy I could help then!

Ivan

> 
> Best regards,
> 
> Tobias
>> Thanks!
>> 
>> Ivan
>> 
>> 
>> On Nov 10, 2010, at 10:59 , Thierry MICHEL wrote:
>> 
>>> Ivan,
>>> 
>>> In your LC comment you had asked to see the new version of our rdf ontology
>>> 
>>> http://lists.w3.org/Archives/Public/public-media-annotation/2010Sep/0241.html
>>> 
>>> It now included in the latest Ontology draft (going for a  2nd LC).
>>> http://dev.w3.org/2008/video/mediaann/mediaont-1.0/mediaont-1.0.html#ont-RDF
>>> 
>>> Please take a look at it and feel free to send feedback.
>>> 
>>> Thierry
>>> 
>>> 
>>> 
>>>> Le 10/11/2010 09:18, Evain, Jean-Pierre a écrit :
>>>>> Dear all,
>>>>> 
>>>>> I am pleased to send you the new version of our rdf ontology following
>>>>> the meeting at TPAC Lyon.
>>>>> 
>>>>> Thank-you to Pierre Antoine, Tobias and Yannick for their active
>>>>> support in this work.
>>>>> 
>>>>> During the TPAC meeting, it was decided that this should become a
>>>>> normative part of the MAWG ontology and therefore we need to respect
>>>>> the deadlines. As a consequence, final comments are due before Monday
>>>>> next week.
>>>>> 
>>>>> All the modifications made to the ontology are listed in comments
>>>>> within the rdf file.
>>>>> 
>>>>> Thierry, if you would be so kind to upload this as our new version.
>>>>> Thank-you in advance.
>>>>> 
>>>>> Best regards,
>>>>> 
>>>>> Jean-Pierre
>>>>> 
>> 
>> ----
>> Ivan Herman, W3C Semantic Web Activity Lead
>> Home: http://www.w3.org/People/Ivan/
>> mobile: +31-641044153
>> PGP Key: http://www.ivan-herman.net/pgpkey.html
>> FOAF: http://www.ivan-herman.net/foaf.rdf
>> 
>> 
>> 
>> 
>> 
> 
> -- 
> ================================================================
> Dr. Tobias Bürger         Knowledge and Media Technologies Group
> Salzburg Research                           FON +43.662.2288-415
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> 


----
Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
mobile: +31-641044153
PGP Key: http://www.ivan-herman.net/pgpkey.html
FOAF: http://www.ivan-herman.net/foaf.rdf