Re: XHTML-RDFa draft made public

Hi Ivan,

Sure...but an HTML author is not going to understand why they need to
add 'plain', and is therefore not likely to do it. So the question
then moves to the triple store, and my worry was that if queries were
written in SPARQL that didn't take into account that foaf:name could
be either plain literal
or a typed literal, things could get messy.

But the good news is that our telecon just resolved that insofar as
there is an issue, it's for server-side programmers, and not authors.
So we're all agreed on the hybrid approach. :)

Regards,

Mark

On 11/04/07, Ivan Herman <ivan@w3.org> wrote:
> Mark,
>
> Mark Birbeck wrote:
> >
> > Hi Elias,
> >
> >> I have not had time to attend the meetings, let alone do my todo on
> >> investigating many ontologies to find the most used. I wasn't worried
> >> because I too thought that we were aiming at consensus on the new style
> >> and not the current. Where are we/you on this? current or new hybrid
> >> approach?
> >
> > The situation is this; there is no immediately obvious 'rule' that we
> > can identify when parsing the document to help us determine whether to
> > use a plain literal or a typed literal.
> >
> > For example, let's say we go the route of the hybrid, and decide that
> > if we see mark-up we use an XML literal, and if don't we use a plain
> > literal. This is fine for the  example of E = mc<sup>2</sup>, but what
> > do we do here:
> >
> >  <tr>
> >    <td>First name</td>
> >    <td>Surname</td>
> >  </tr>
> >  <tr property="foaf:name">
> >    <td>Elias</td>
> >    <td>Torres</td>
> >  </tr>
> >  <tr property="foaf:name">
> >    <td>Ivan</td>
> >    <td>Herman</td>
> >  </tr>
> >
> > In this situation the mark-up is purely structural, and plays no role
> > in the actual metadata itself.
> >
>
> I am not sure I understand. In Ben's review of the issues:
>
> http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2007Mar/0096.html
>
> this was the case of the datatype="plain". Ie, I would say
>
> <tr property="foaf:name" datatype="plain">
>         <td>Elias</td>
>         <td>Torres</td>
> </tr>
>
> that would result in
>
> <....> foaf:name "Elias Torres"
>
> I may miss something but this seems to be covered by the hybrid view,
> but I do not see any disagreement we might have had on the subsequent
> thread...
>
> > So the hybrid view is not as good as it first appeared, I'm afraid.
> >
> > On the two telecons where we have discussed this, we decided that the
> > choices seemed to be:
> >
> > * remove the mark-up completely and parse to plain literals;
> >
> > * go with the existing approach of using XML literals;
> >
> > * modify the 'hybrid' solution so that different elements have
> > different behaviour.
> >
>
> You mean different HTML elements? That would be awful. But, as I say, it
> looks to me that the hybrid view could work well.
>
> > It was felt that removing all mark-up (option 1) was a last resort,
> > and we should try to avoid it if we can, since we'd be losing
> > information.
> >
> > It was also felt that having different behaviour based on the mark-up
> > (option 3) could get too complicated, although I'm not so sure it
> > would be that difficult; we could say that only inline elements such
> > as <em>, <sup>, etc. trigger parsing as XML literal, whilst others
> > don't.
> >
> > And it was generally agreed that although it may have other problems,
> > the current 'XML literal' approach at least had the benefit of
> > preserving all mark-up, and so allowing the users of the triples to
> > decide whether the mark-up was significant or not. (This is easily
> > done using functions provided in SPARQL.)
> >
>
> I do not want to reopen the thread here:-) I guess you know my opinion...
>
> Ivan
>
>
> --
>
> Ivan Herman, W3C Semantic Web Activity Lead
> URL: http://www.w3.org/People/Ivan/
> PGP Key: http://www.cwi.nl/%7Eivan/AboutMe/pgpkey.html
> FOAF: http://www.ivan-herman.net/foaf.rdf
>
>


-- 
  Mark Birbeck, formsPlayer

  mark.birbeck@x-port.net | +44 (0) 20 7689 9232
  http://www.formsPlayer.com | http://internet-apps.blogspot.com

  standards. innovation.

Received on Wednesday, 11 April 2007 14:04:38 UTC