W3C home > Mailing lists > Public > public-media-annotation@w3.org > January 2009

Re: action 78 - Discussion about interoperability

From: Pierre-Antoine Champin <pchampin@liris.cnrs.fr>
Date: Tue, 27 Jan 2009 16:45:24 +0000
Message-ID: <497F3A24.9090809@liris.cnrs.fr>
To: Tobias Bürger <tobias.buerger@sti2.at>
CC: public-media-annotation@w3.org

Tobias Bürger wrote :
> Regarding the mapping, and more specifically from where we should map:
> The mapping should be to our core ontology to whose semantics we
> committed ourselves or will commit. So we will define what we allow as
> the domain and range of a property.

Agreed. But defining the range of the a property can be done at several
levels:

- high-level/human semantics (e.g. Creator : the agent primarily
responsible of creating the resource)

- low-level/machine semantics (e.g. an instance of dcterms:Agent OR the
name of such an instance)

- syntax (e.g. a Uri OR a String)

> And I disagree to the last statement from Pierre-Antoine above: if we
> describe the ontology less specific than we also do not need to be more
> precise in the API. It has been my understanding that this group defines
> an ontology consisting of a set of core properties for the description
> of media objects on the Web to which all the formats in our scope will
> be mapped to. Saying that, if you describe the ontology more
> lightweight, meaning perhaps with less detail or level of specifity,
> than you also map to something not very specific.

I think you misunderstood my statement. I should not have written
"specific" but "formal".
It is not about defining only "creator" vs. "composer" and "writer"
(specific), but about defining only high-level semantics vs. defining
also low-level semantics and syntax.

High-level semantics clearly belongs to the ontology.
Syntax clearly belongs to the API.
Low-level semantics, on the other hand, can be discussed. We could also
describe it formally, using a formal ontology language (this is what
those languages are about). Or we  could describe it only as prose, as
Felix suggest.
If we choose prose, then we have the choice to put it in the ontology or
API specification. Hence my statement "the less specific we are in
describing the ontology, the more precise we will have to be in
describing the API".

Thank you Tobias for having me explain that: it helped me make my ideas
on the subject much clearer to myself :)

I hope this makes sense for others as well :-P

> For me the API is a means to transparently access a description of a
> media object in a format about which I do not want to care about when
> accessing the API.

+1

> So we should define return types? Or should the
> burden of identying the return type be shifted to the user? (I guess we
> had this discussion before but did not come to a conclusion....)

I think tha we should not only define return types (that is the easy
part: syntax); we should also specify the "content" of the return value,
which involves high-level AND low-level semantics.

  pa
Received on Tuesday, 27 January 2009 16:46:06 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 27 January 2009 16:46:09 GMT