W3C home > Mailing lists > Public > public-owl-wg@w3.org > November 2007

Re: Rich Annotation System Proposal

From: Achille Fokoue <achille@us.ibm.com>
Date: Tue, 6 Nov 2007 22:17:44 -0500
To: Bijan Parsia <bparsia@cs.man.ac.uk>, "Web Ontology Language (OWL) Working Group WG" <public-owl-wg@w3.org>
Message-ID: <OFF969CE92.BAD3E1BF-ON8525738C.000C0A1C-8525738C.00121A56@us.ibm.com>
>(Is there a reason why you cc public-owl-wg-request@w3.org? Seems 
>odd...)
No, this is just the default behavior of my email client when I press the 
reply button. Thanks for pointing it out!

>>
>> >> 2.  For an annotationByBlob, which enables arbitrary assertions,
>> >> limiting the content to facts makes sense.  However, allowing
>> >> arbitrary XML, as you suggested could be done in principle, might
>> >> raise issues related to the translation of arbitrary XML content
>> >> into RDF.
>>
>> >Well, my thought is that not all annotations need be translatable to
>> >RDF. If someone wants to associate, I don't know, SVG or SVG
>> >fragments with some entity or axioms...who am I to disagree? Or
>> >perhaps someone wants to use a RIF XML dialect, or what have you. I
>> >don't see a huge advantage in *requiring* a property to a literal in
>> >the annotation, though that's probably harmless, just a little
>> >annoying for the XML person.
>>
>> My concern here is that we won't be able to go from XML to N3 or 
>> RDF/XML representation without loosing information, which seems to 
>> give a higher status to the XML representation.

>Why? I mean, isn't this just a function of the RDF mapping? You can 
>always map:
> 
>                SubClassOf( Annotations("<b>Hiya Mom!</b>"), C, D)
>
>to
>                _:x a Statement.
>                _:x hasAnnotationBlob "<b>Hiya Mom!</b>".
>                #rest of the reified statement
>
> so what's the problem?

I think that, in your example, the structure of the content of the 
annotation has been lost: it appears only as a string literal.  If we 
could somehow restrict the content of annotations to RDF/XML, we would 
then also easily preserve the structure of the annotation in the RDF 
representation. 

        SubClassOf( Annotations(<rdf:Description><b>Hiya 
Mom!</b></rdf:Description>), C, D)

                _:x a Statement.
                _:x hasAnnotationBlob _:y.
                _:y a Statement.
                _:y rdf:predicate b.
                _:y rdf:subject _:x.
                _:y rdf:object "Hiya Mom!".
                 #rest of the reified statements

Note that this restriction to RDF/XML does not prevent you from encoding 
as string literal arbitrary XML content. This can be done by using XML 
CData section as illustrated by the following example:
        SubClassOf( Annotations(<rdf:Description>
<b><![CDATA[<a><c/><d>piece of an arbitrary XML</d></a>]]> 
<b></rdf:Description>), C, D)
                _:x a Statement.
                _:x hasAnnotationBlob _:y.
                _:y a Statement.
                _:y rdf:predicate b.
                _:y rdf:subject _:x.
                _:y rdf:object "<a><c/><d>piece of an arbitrary 
XML</d></a>"
                 #rest of the reified statements

To conclude, I would like to preserve as much as possible the structure of 
the content of annotations in the RDF representation. 

>Just because the *content* of an annotationAssertions is arbitrary 
>XML doesn't mean that an annotationByBlob can't be RDFed.
>
>This isn't saying that arbitrary XML is necessary, but I don't 
>understand your objection.

I hope that I have clarified my concern.

Thanks!
Achille.
Received on Wednesday, 7 November 2007 03:18:11 GMT

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