Re: reusing vocabularies / mapping withowl:equivalentClass

Hi,

I'm all for reusing existing terms, see below.

On 14.10.2008, at 10:48, Thomas Loertsch wrote:

> Hi there,
>
> I want to derive a RDFa format from a microformat, an experimental  
> version
> of hRecipe in this case. I think of them both as serializations of a
> vocabulary. To make the distiction clearer I'll call them vRecipe (the
> implementation-neutral voacbulary), hRecipe (the microformat) and  
> aRecipe
> (the RDFa format).
>
> I'm unsure how to map the vRecipe to RDFa. Should I reuse existing
> vocabularies or should I develop a new one and then provide an OWL  
> mapping
> to existing vocabularies?
>
> E.g. there's a title-element in vRecipe, called 'recipe-title'. In  
> hRecipe,
> the microformat serialization, it's called 'recipe-title' as well.  
> Since
> RDFa provides namespacing mechanisms it could be called  
> 'hRecipe:title'
> here. A mapping from 'hRecipe:title' to 'DC:title' -
>
>    hRecipe:title owl:equivalentClass dc:title

During VoCamp Oxford last month a number of people including me  
discussed the problem that in the SW world there are too many  
different terms (properties and classes) that mean the same thing (or  
almost the same thing). Your title property is probably the best  
example: almost every new ontology or vocabulary mints their own new  
URI for saying "this is the name of that". There is rdfs:label,  
dc:title, foaf:name, sioc:title, doap:title, skos:prefLabel, ical:summary 
, ... A lot of ontology designers then go about and say that their new  
name/title/label property is a subproperty of rdfs:label, or  
equivalent to it. But as you say yourself, these assertions will only  
help if the right kind of reasoning is performed - and this, I'm  
afraid, mostly doesn't happen. The fact that RDF tools can parse the  
data doesn't solve the problem, because after that you'll also want to  
_do_ something witht the data. E.g., as a result, it is quite hard to  
query an RDF store for something basic such as "list me all the  
resources you have and their name". If there is no reasoning taking  
place, then all you can do is to include all possible label properties  
in the query, which is obviously not feasible.

So, long story short: I think everyone should try to use the same  
properties and classes all the time, if possible, and as long as  
reasoning cannot be taken for granted. Maybe during the next VoCamp in  
Galway, I'm hoping to put together something like a "vocabulary  
starter pack" for the SW, suggesting a property or class for some  
basic annotation needs such "this is the name of that". I'm not sure  
yet how good the idea is, but I have a feeling something like that  
would be beneficial.

Cheers,
Knud

> - would make it clear that both are semantically equivalent.  
> Although in
> this example it's not obvious why not to use a straightforward  
> mapping to
> the wellknown DC:title in the first place, but the whole vRecipe  
> vocabulary
> needs mappings to a whole bunch of other vocabularies, some of them  
> not so
> well known, and it looks quite messy when mapped straightforwardly.  
> It would
> surely look much prettier - and was much easier to comprehend and  
> use - if
> it was developed from scratch (and from the vRecipe voacbulary  
> respectively)
> in a coherent way and *then* mapped to other, already existing  
> vocabularies
> with owl:equivalentClass.
>
> I can see that the use of OWL adds complexity and that OWL can't be  
> handled
> "meaningfully" by simple RDF tools but I'm not sure how much of a  
> problem
> that is. Simple RDF tools can surely parse it which would be enough  
> for a
> lot of usage scenarios. The whole power of the semantic web otoh  
> only comes
> with RDFS and OWL and therefor it seems okay to me to use them like  
> I did
> above. Or am I adding complexity where I really shouldn't?
>
> Cheers,
> Thomas
>
>
> ..
> Thomas Lörtsch
> Living at Home Multi Media GmbH
> Redaktion Online
> ...
> Stubbenhuk 5
> 20459 Hamburg
> ....
> eMail: loertsch.thomas@guj.de
>
>
>
>

-------------------------------------------------
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 Tuesday, 14 October 2008 13:44:29 UTC