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Re: expectations of vocabulary

From: Henry Story <henry.story@bblfish.net>
Date: Sat, 22 Jul 2006 19:42:34 +0200
Message-Id: <4A89063C-4D03-444A-98E6-15E3D4EE807F@bblfish.net>
To: Semantic Web <semantic-web@w3.org>

Sean B. Palmer gave me some very feedback on this on the #swig irc  
channel.
You can read it here:
    http://chatlogs.planetrdf.com/swig/2006-07-22.html#T16-47-03

Sean even had put forward a paper on the subject in 2003
    http://infomesh.net/2003/graphsl

This problem has also occurred on the foaf newsgroup when trying to  
work out what a foaf:Document exactly is.

It looks like there are solutions that can be developed here, that  
would be something like xml schema or relax ng for rdf. I think this  
would be very useful in many areas of the semantic web.

It would for example allows us to say that a foaf:Document is a  
document that must contain a statement about an entry or a resource,  
that that thing must have an id that is stated, a title that is  
stated, etc... This is different from the semantics.

It would then be possible for example to create a foaf:PostDocument  
that would be like a foaf:Document, except that the id need not be  
stated. A foaf:PostDocument would be something one could POST to a  
collection (the server would determine the id)


Henry


Home page: http://bblfish.net/
Sun Blog: http://blogs.sun.com/bblfish/



On 21 Jul 2006, at 17:21, Henry Story wrote:

>
> RDF solves the mime type explosion problem. Everything can be  
> expressed in one of the RDF mime types (I'll use N3 here cause it's  
> easier to write). But has the mime type explosion problem just been  
> shifted?
>
> Below is an example that should help illustrate the problem.
>
> Example
> -------
>
> Imagine I translate the following atom
>
> <entry>
>    ...
>    <link rel="categories" href="/cats"/>
>    ...
> </entry>
>
> into the following N3
>
> [] a :Entry;
>   iana:categories </cats> .
>
> Where I have defined
>
> @prefix iana: <http://www.iana.org/assignments/relation/> .
> @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
> @prefix owl: <http://www.w3.org/2002/07/owl#> .
>
> iana:categories a owl:ObjectPropery;
>                 rdfs:domain :FeedOrEntry;
>                 rdfs:range :CategoryList .
>
>
> The N3 representation of </cats> could be something like
>
> <> a :CategoryList;
>    :category [ :scheme <http://eg.com/cats/>;
>                :term "dog" ];
>    :category [ :scheme <http://eg.com/cats/>;
>                :term "house" ].
>
>
>
>
> Question
> --------
>
> What guarantee do I have that  the representation returned is not
>
> <> a :McDonaldCategoryList;
>    :McCategory [ :McScheme <http://eg.com/cats/>;
>                :McTerm "dog" ];
>    :McCategory [ :McScheme <http://eg.com/cats/>;
>                :McTerm "house" ].
>
> where the above terms are all defined somewhere as being owl:sameAs  
> the ones I was expecting to receive?
>
>
> Solution?
> --------
>
> Well perhaps one could argue that :categories is a relation that  
> creates an expectation of things being represented in a certain  
> way. But since we are dealing with semantics, that seems a little  
> dodgy.
>
> Perhaps it is just expectations and conventions that we use the  
> same vocabulary that will solve this problem. After all that is  
> just what happens in normal language learning
> (See perhaps Devid Lewis's book Convention)
>
> Henry
>
>
> Home page: http://bblfish.net/
> Sun Blog: http://blogs.sun.com/bblfish/
>
>
>
Received on Saturday, 22 July 2006 17:42:48 GMT

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