Re: [Proposal] ISSUE-42: How does RDFa deal with @src

Keith Alexander wrote:
> Ivan wrote:
>> Actually, I am not convinced of that. I guess It is a question of
>> general approach: I'd somehow prefer, as an author, _to be in control_
>> over _all_ triples that are generated, and avoid any automatism. I may
>> put in the 'alt' tag into my HTML file for reasons of accessibility, for
>> example; I may _not_ want that information to appear in the triples.
>>
> Mark wrote:
>> First, what is the downside of adding extra triples, as long as they
>> are consistent? You don't need to use them, after all. (I'm not saying
>> there isn't a downside, just asking if anyone can think of one.)
> 
> eRDF also generates rdfs:label triples for img and anchor elements,  and
> I've had problems with this generation of triples that I'm not in
> authorial control over.
> 

> What I was doing was taking the triples generated from a php template
> marked up with eRDF, and using that to generate SPARQL queries. So the
> extra triples were a nuisance because  it would add conditions I didn't
> want to my generated queries, which made them return different results.
> So I wrote my own parser that made the generation of these extra triples
> optional.
> 


Wow. That is a use case I have not even thought about. Thanks!

Ivan


> To be fair, that's a fringe  use of RDF-in-HTML, but you could take it
> as an example of unintended negative consequences when you try to do too
> much and don't give the author control. As I've said before, I think
> RDF-in-HTML is an interesting space, and I reckon there are lots of uses
> for it still waiting to be discovered, so it's worth bearing in mind
> that magical automation can often be more annoying than helpful (like
> the paperclip in MS Word ;) ).
> 
> On the other hand, when trying to write software that displays RDF,
> rdfs:labels are very nice to have. Exhibit (from Simile) now allows you
> to use any RDF on the web to power your exhibit (on the fly), but if the
> resources don't have rdfs:label properties, then the software falls back
> to these long, unfriendly-looking, generated id strings. So I can also
> see that it makes your RDF more useful if the resources are nicely
> labelled, and it's definitely easier to write software if you can rely
> on labels being present.
> 
> However, on balance, I think it's better to leave the author in full
> control over the triples generated as default behaviour.
> 
> Cheers
> 
> Keith
> 
> ps: I'd also chime in agreement with what Dan was saying about not
> assuming anything that you can parse into some triples /is intended/ to
> parse into those triples. For example, since the RDFa syntax is still
> being finalised, it doesn't seem improbable that there might be RDFa out
> there that wouldn't now parse into the triples that the author intended
> when s/he wrote the html.
> 
> Authorial intention is key.
> 
> 

-- 

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