- From: Ivan Herman <ivan@w3.org>
- Date: Fri, 22 Jun 2007 14:06:06 +0200
- To: mark.birbeck@x-port.net
- Cc: RDFa <public-rdf-in-xhtml-tf@w3.org>
- Message-ID: <467BBB2E.7080302@w3.org>
Mark Birbeck wrote: > Hi Ivan, > > Fair comments, but I'd like to follow this through a bit more. > > 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.) > Yeah. That is also true... > I ask because I often find when trying to make use of the triples to > enhance a document, that you invariably need a label for the things > that you find in the document. Take a simple example, like a semantic > web browser that parses the RDF in a document (whether RDFa, > microformats, links to RDF/XML, etc.), places the triples in a data > store, and then provides options to the user on things they can do > with that data. Now, with data like a foaf:Person it's probably quite > easy, since you can display a menu option like "Add Ivan Herman's > details to your address book." But it becomes more difficult when you > want to display a menu option like "Upload 'portrait photo for Ivan' > to Flickr" or "Add tags to 'portrait photo for Ivan' to Flickr", if > you don't actually have some text to use. > > The problem I keep coming up against is that the software I'm working > on constantly needs to go back to the original document to get > information that it can make use of, which feels wrong to me. I should > be able to 'act' on the data regardless of its source--or to put it a > different way, I should have everything I need in the triple store. > > You could extend this logic to cover accessibility too; in the future > I'd imagine that accessibility software could make use of the triples > generated, just as much as it makes use of the source document. > We may get close to something ugly, namely some sort of an RDFa profiling (do _not_ eat me alive!). What I mean is that there may be different of RDFa processors that either do a minimal triple extraction, or do some extra work extracting extra semantics from the HTML content. I am not sure how to control that... Yes, I know it is ugly!:-) > But.... :) > > As long as we don't rule this out for the future it's not a problem to > me if we leave it to one side for now. If you still disagree with > processing @alt and/or @longdesc I don't have a problem with marking > this as something we come back to in a future iteration. > I think that, at the moment, we should try to do the minimum, ie, no extra triplets, and see how the application(s) of RDFa evolve in the community. This is also a question of consistency: you have a list of other elements where the issue may come up, and, again, where do we stop? I do not feel really comfortable on what exactly such extra HTML->RDF mappings should be. I am not even sure that different communities would opt for the same mapping, we may have different approaches around and spend _lot_ of time sorting that out... I know I am a bit vague, nothing mathematically precise here... Cheers Ivan > Regards, > > Mark > > On 22/06/07, Ivan Herman <ivan@w3.org> wrote: >> >> >> Mark Birbeck wrote: >> > Hi Ivan, >> > >> >> B.t.w., I realized yesterday evening (under the shower, the best place >> >> for these things:-) that this is wrong. >> > >> > :) >> > >> >> The range of rdfs:seeAlso is >> >> defined to be rdf:Resource by the RDF Semantics, ie, it should not be >> >> used with a Literal as an object. >> > >> > Right. That's why I was wondering if rdfs:seeAlso was a better choice >> > for @longdesc than dc:description, since @longdesc takes a URI. I'd >> > forgotten about rdfs:seeAlso until I saw your post. >> > >> > >> >> But there is also rdfs:comment, for >> >> example, that could be used instead of rdfs:label, so the original >> >> argument holds... >> > >> > Sure...I think you are right that there are better choices than >> > rdfs:label. We just need to alight on one and go with it. (And I >> > assume that your comment is a +1 for the idea that @alt should >> > actually be represented in triples, even if we're not yet sure what >> > triples?) >> > >> >> 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. >> >> As a simple example: if I use an HTML file for my foaf file, too, I may >> have an image in that HTML file. As an HTML file I might put there an >> alt text with a pretty uninformative text like "portrait photo for Ivan" >> which is there so that screen readers would convey an information to a >> blind reader that, in fact, this photo is without an further info and is >> put there to make seeing people happy. While the photo reference would >> go into the foaf file as a depiction, and that is fine, generating an >> extra rdf:comment or rdf:label or anything else _automatically_ is a >> side effect of the mechanism that I may not want at all. >> >> Bottom line: no, I am not convinced. >> >> Ivan >> >> >> > Regards, >> > >> > Mark >> > >> >> -- >> >> 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 >> >> > > -- 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
Received on Friday, 22 June 2007 12:06:07 UTC