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Re: In RDF what is the best practice to represent data provenance (source)?

From: Sandro Hawke <sandro@w3.org>
Date: Thu, 18 Jan 2007 12:50:54 -0500
To: Richard Cyganiak <richard@cyganiak.de>
Cc: Michael Schneider <m_schnei@gmx.de>, chris@bizer.de, semantic-web@w3.org, semantic_web@googlegroups.com
Message-Id: <20070118175108.E9F4D4EF11@homer.w3.org>


> Enter named graphs.
> 
>      :michael_graph {
>          :reification :is_great_for :provenance_tracking .
>      }
...
> And accommodating the contributions of Bob, Charlie and Dora is  
> straightforward.
> 
> See why reification does not have many friends?
> 
> Surprisingly, some people choose to use reification nonetheless. Why  
> is this so? Is it just because its unfinished empty concrete shell  
> was left in the RDF spec? I never found a real reason, neither  
> technical nor modelling.

I see named graphs, as you present them, as a concept without an RDF
syntax.  Reification in general is a way to give named graphs an RDF
syntax.  Reification as defined in the current W3C specs is an
incomplete approach giving named graphs an RDF syntax.  It handles only
individual statements, not whole graphs, and it doesn't handle bnodes.

You could argue that named graphs should not have an RDF syntax.  I
would argue that everything should have an RDF syntax when it becomes
useful to somebody to give it one.

Of course you probably want syntactic sugar (eg curly braces), since
working with reified graphs is so verbose, but there are lots of things
in RDF you want syntactic sugar for.

      -- Sandro
Received on Thursday, 18 January 2007 17:51:13 UTC

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