- From: Ruben Verborgh <ruben.verborgh@ugent.be>
- Date: Thu, 1 Mar 2012 09:17:54 +0100
- To: Michael Hausenblas <michael.hausenblas@deri.org>
- Cc: public-rdf@w3.org, public-rdf-wg@w3.org, W3C SWIG Mailing-List <semantic-web@w3.org>
Hi Michael, > Are you aware of http://sioc-project.org/ …? Thanks for your reply. I’m aware of the SIOC project. As far as I can see, they do not have a solution for this problem. While they have the :has_reply predicate, they do not have a mechanism to identify all replies to a post. Note that the “blog post” use case is just an example. In fact, it could be anything collection-related (the relation from a book to its reviews, from a social graph to its members, …). The general question is: RDF is great to express individual relations between resources A and B1, B2, B3… but how can it express the relation between A and the set of all resources Bx? Best, Ruben > On 1 Mar 2012, at 07:28, Ruben Verborgh wrote: > >> Dear Semantic Web enthousiasts, >> >> Suppose we have a Web application for blogging: >> - /posts/35 is a blog post >> - /posts/35/comments are the comments to that post >> - /posts/35/comments/3 is a specific comment to this post >> >> In RDF, it is straightforward to make the relation between the blog post and a specific comment: >> </posts/35> :hasComment </posts/35/comments/3>. >> It is also easy to describe the relation between a specific comment and all comments: >> </posts/35/comments/4> :memberOf </posts/35/comments>. >> >> However, how do we indicate the relationship between the blog post and *all* comments that belong to it? >> I.e., what is the relationship between </posts/35> and </posts/35/comments> ? >> >> One could make a new predicate for that of course: >> </posts/35/> :hasComments </posts/35/comments>. >> But then, we still have to explain the relation between :hasComments and :hasComment; and we’d have to do that for every such plural predicate. >> >> This seems to be a fundamental problem. >> Clearly, the resource “comments on blog post 35” exists, but there doesn’t seem to be a straightforward way to describe it in RDF. >> RDF lists will not be sufficient: they could indeed explain the relation between a specific comment and all comments, but not the relation between all comments and the blog post. >> Also note that the indirect relation “_:x :hasComment _:y. _:y :memberOf _:z” is not sufficient: a blog post can have no comments, but even then it still has an (empty) comments resource. >> >> Have you encountered this issue and how do you solve it? >> >> Kind regards, >> -- >> Ruben Verborgh >> http://twitter.com/RubenVerborgh >> PhD Student at Multimedia Lab – IBBT / ELIS, Ghent University, Belgium >> >> Make your hypermedia API ready for intelligent agents via http://restdesc.org/. >> >> >
Received on Thursday, 1 March 2012 08:18:32 UTC