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Re: Semantic content negotiation (was Re: expectations of vocabulary)

From: Richard Newman <r.newman@reading.ac.uk>
Date: Sat, 29 Jul 2006 22:29:18 -0700
Message-Id: <E875D3C4-ADA0-4489-A545-FA4A241727CB@reading.ac.uk>
Cc: =?ISO-8859-1?Q? "'Reto_Bachmann-Gm=FCr'" ?= <reto@gmuer.ch>, "'Semantic Web'" <semantic-web@w3.org>
To: "Xiaoshu Wang" <wangxiao@musc.edu>

... and a 2 input to the rest of the discussion, too:

Accept-vocabulary does not put a burden on the ontology developer. It  
does run a risk of drastically reducing the amount of information  
sent in response to a request, but that is not necessarily a bad  
thing. Ontology developers -- and, indeed, data producers -- should  
use the correct terms regardless.

Assuming that Accept-vocabulary is defined as "I would prefer to  
receive this vocabulary, but can accept others", then a sufficiently- 
smart server can try to provide suitable triples as a representation  
of the resource. A dumb server can return whatever it likes,  
including other vocabularies, ignoring the special request entirely  
if it so chooses.

Assuming that it is defined as "I can only use vocabularies X, Y, and  
Z; anything else is useless to me", then a sufficiently-smart server  
can use whatever means necessary to provide an RDF representation  
about the resource in those vocabularies to the client. If no such  
triples exist, it can return an empty graph. A dumb server can simply  
return the subset of triples that it would have returned to a  
conventional request -- consider this server-side vocabulary filtering.

I can imagine the former being very useful for automatic ontology  
translation; if I maintain a personal profile, maybe linked to a  
database, I can tell my server a whole bunch of mappings (perhaps to  
FOAF, vCard or custom ontologies), and allow it to answer requests  
using the terms that the client wishes to use.

I can imagine the latter being very useful for limited devices, such  
as mobile phones. A phone is unlikely to have a smart reasoner with  
ontology mappings, so it *really* can't use triples in terms of  
vocabularies for which it was not designed. Separating the wheat from  
the chaff before transmission seems helpful.


On  29 Jul 2006, at 8:52 PM, Xiaoshu Wang wrote:

> Problem 1: an RDF document can be written in multiple similar  
> vocabularies.
> Use Accept-vocabulary to ask the server to return the statement  
> written in
> certain vocabularies but not the other.
> My position for this problem (let's call it alternative vocabulary  
> problem).
> It is O.K., fundamentally.  But I don't think it is practical.  It  
> puts too
> much burdern on ontology developer.  It is cheaper and easier doing  
> this
> sort of things at other places.
> Problem 2: Let's call this subgraph problem.  I.e., the Accept- 
> Vocabulary
> ask the server to return only those subgraphs that the client request.
> My position to this problem. No.  It is fundemantally wrong and we  
> should do
> it with a web service etc., using SPARQL.
Received on Sunday, 30 July 2006 05:29:32 UTC

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