Raw

Olaf Hartig has pointed me to the R2R Framework :

[[

The R2R Framework enables Linked Data applications which discover data on the Web, that is represented using unknown terms, to search the Web for mappings and apply the discovered mappings to translate Web data to the application's target vocabulary. The R2R Framework is aimed to be used by Linked Data publishers, vocabulary maintainers and Linked Data application developers. It support them by:

1. providing the R2R Mapping Language for publishing fine-grained term mappings on the Web

2. defining best-practices on how mappings can be discovered by Linked Data applications

3. providing an open-source implementation of the R2R Mapping Engine.

]]

I just heard about a mapping from selected schema.org terms to SIOC (including a little FOAF and DC), it's a handful of statements using RDFS and OWL.

As one of the people responsible for the RDF Review Vocabulary I thought I should take a look what's needed there. It raises a couple of questions. As it happens, schema.org's model for reviews is a little more complex than our RDF vocab (after we went to all that trouble to keep it simple :), and a lot of the terms can't be mapped directly to well-known ones with RDFS/OWL.

e.g. in the RDF vocab:

<#something> :rating "5" .

using schema.org:

<#something> :reviewRating <#theRating> :ratingValue "5" .

So the first question is how best to express this? I think it's straightforward in SPARQL, e.g. for RDF vocab to schema.org for the terms above something like:

CONSTRUCT {

?something s:reviewRating [ :ratingValue ?value ]

} WHERE {

?something r:rating ?value

}

Or would some particular rule language be more appropriate?

The next question is how best to publish the mappings?

Where direct RDFS/OWL translation is possible, I think I'd be inclined towards including them in the RDF vocab, or at least linked via an rdfs:seeAlso.

Where rules are necessary, as above, I really haven't a clue. A simple online reasoning service could be useful (via some pre-cooked SPARQL maybe), but again how would you express that in the vocab?

I doubt I'll have chance to make the translations for Review in the near future (one contract I'm 7 weeks past deadline, another 3 weeks overdue, a couple of days overdue with those paper reviews...). But hopefully the lazyweb will be able to answer these questions in the interim.

That's a point - anyone fancy reimplementing lazyweb.org? It was very sweet, I think Ben only gave up on it due to lack of time to admin.

Oh yeah, and I still haven't implemented comments here yet, so for now please use email, Twitter, Facebook or Google+. (ooh, the Google+ link works properly for comments, but I guess non-G+ user can't comment...let me know if you want an invite)