- From: Knud Hinnerk Möller <knud.moeller@deri.org>
- Date: Mon, 30 Jul 2007 19:57:47 +0100
- To: Mark Birbeck <mark.birbeck@formsPlayer.com>
- Cc: Dan Brickley <danbri@danbri.org>, Manu Sporny <msporny@digitalbazaar.com>, public-rdf-in-xhtml-tf@w3.org
- Message-id: <31F3086E-EDD3-4621-A90B-B51ACEBA4288@deri.org>
Ok, here is my use case, if I remember correctly: - I generate RDFa (using the SWRC ontology) from BibTeX - a paper has multiple authors - there are many ways to represent that in RDF - SWRC just uses multiple (book swrc:author aFOAFPerson) statements for that - however, that doesn't keep the order of the authors - that's why I _also_ use one (book swrc_ext:authorList sequenceOfAuthors) statement - I do both because I want to stay compatible to the original SWRC, but also give the possibility of getting the author order - of course the foaf:Person resources in both approaches should be the same - I don't have URIs for the authors, so I need to use bnodes (or make up URIs, which I don't want to do) - because I want to refer to the same resource through both swrc:author and swrc_ext:authorList, I need to be able to name the bnodes within that graph - i.e., I need named bnodes I hope that makes sense. :) Cheers, Knud Am 30.07.2007 um 18:18 schrieb Mark Birbeck: > > Hi Dan/Knud, > > The issue isn't bnodes, since we do have those in RDFa. The question > is whether to support 'named bnodes', which you get in RDF by using > @nodeID. (Early drafts of RDFa actually used to have a nodeID > attribute.) > > I'm really interested to hear comments on the use-cases for this, > which will most likely come from those who use RDF a lot. The main > argument for its use in RDF more generally is to be able to have a > bnode that can be referenced from within a graph, but that cannot be > referenced outside that graph. In RDFa terms that would mean that you > have created a bnode that you want to be able to refer to in some > other part of the document, but you *don't* want anyone else in the > world to be able to make statements about it. > > I can't think of any situations where I'd use that myself, but that > doesn't mean a thing. :) > > Regards, > > Mark > > On 30/07/07, Dan Brickley <danbri@danbri.org> wrote: >> >> Knud Hinnerk Möller wrote: >>> Hi, >>> >>> Am 30.07.2007 um 17:15 schrieb Manu Sporny: >>> >>>> Mark Birbeck wrote: >>>>> I haven't had a chance to re-read this thread, so I'm not going >>>>> to say >>>>> anything on the substance. But if you don't mind, I'd like to >>>>> comment >>>>> on a recurring theme, which seems exemplified by the following: >>>>> >>>>>> I have a visceral problem with about="_:", and that is that it >>>>>> makes >>>>>> bnodes explicit, which I really don't want to do to HTML >>>>>> authors. That's >>>>>> just too much RDF. >>>>>> >>>>> I don't see the need to 'protect' authors who are not familiar >>>>> with >>>>> RDF from RDF constructs that they will never use. If someone >>>>> from the >>>>> RDF community thinks this is useful, and _if_ we can support it >>>>> without it getting in the way, then why not? >>>> >>>> Constructs such as "_:" are scary to non-RDF folks. :) From a >>>> historically RDF-unaware perspective (mine), I stared at the "_:" >>>> construct and had no idea what it does. It is not very intuitive. >>>> >>>> Even having seen it, I haven't taken the time to look up what it >>>> means. >>>> It will probably make sense when I do, but to somebody that is not >>>> trained in CS/EE/ECE/etc., this is a scary construct. To the lay >>>> web >>>> page author, it is syntactic gibberish. >>>> >>>> There is already a very strong feeling in the Microformats >>>> community >>>> that RDFa is far too complicated for most web page authors. The >>>> last >>>> thing most of them want to learn is yet another language syntax for >>>> describing what they see as "corner-cases of the language". >>>> >>>> I see your argument: If they aren't going to use it, and if it >>>> doesn't >>>> cause any harm, then why not put it in there? >>>> >>>> I would argue that you shouldn't put things in there that aren't >>>> absolutely necessary. It complicates the RDFa specification. If >>>> there is >>>> a need in the future, you can always add it in a later revision. >>> >>> I would really argue to have bnodes in RDFa: I know they are very >>> unpopular, and vocabularies like FOAF now recommend against using >>> them. >> >> No they don't :) well, foaf in particular... >> >> I put a #me into the FOAF spec example, that's all. >> >> RDF is a language for representing and aggregating partial >> information >> into a greater whole. Sometimes that information lacks statements, >> sometimes those statements are missing well known identifiers. >> Sometimes >> the things the statements are about don't even have well known >> identifiers. >> >> There are things in FOAF such as isPrimaryTopicOf which are >> designed to >> help people live in such a world. But there is nothing FOAF or >> other RDF >> vocabs can do to get away from the basic fact: informational is not >> universally and evenly available. RDF authors do not have a godlike >> access to every fact and every identifier they might need. And so RDF >> data is inevitably a lossy, gappy thing. Sometimes missing >> statements, >> sometimes missing URIs. Because RDF is written by people, and >> people do >> not know everything. If they did, why would they bother exchanging >> RDF >> files with each other? :) And so we have bnodes. >> >> That said, "_:" in RDFa worries me too. >> >> Dan >> >> > > > -- > Mark Birbeck, formsPlayer > > mark.birbeck@formsPlayer.com | +44 (0) 20 7689 9232 > http://www.formsPlayer.com | http://internet-apps.blogspot.com > > standards. innovation. ------------------------------------------------- Knud Möller, MA +353 - 91 - 495086 Smile Group: http://smile.deri.ie Digital Enterprise Research Institute National University of Ireland, Galway Institiúid Taighde na Fiontraíochta Digití Ollscoil na hÉireann, Gaillimh
Received on Monday, 30 July 2007 18:59:48 UTC