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Re: Context Tags, Context Sets and Beyond Named Graphs...

From: Jeni Tennison <jeni@jenitennison.com>
Date: Mon, 18 Jan 2010 19:56:47 +0000
Cc: Paul Houle <ontology2@gmail.com>, public-lod <public-lod@w3.org>
Message-Id: <7D57C9DD-7F3C-4A6F-ABC8-EC72F89D00A5@jenitennison.com>
To: Leigh Dodds <leigh.dodds@talis.com>
Leigh,

Do you think that http://www.w3.org/2004/03/trix/rdfg-1/ is sufficient  
for describing the relationships between graphs (for these purposes)  
and if not, what do you think needs adding?

Jeni

On 18 Jan 2010, at 19:20, Leigh Dodds wrote:

> Hi Paul,
>
> 2010/1/18 Paul Houle <ontology2@gmail.com>:
>> For a while I've been struggling with a number of practical  
>> problems working
>> in RDF.  Some of these addressed by Named Graphs as they currently  
>> exists,
>> but others aren't.
>
> Looks to me like you need Named Graphs plus a mechanism to describe
> combinations of graphs.
>
>> Over the weekend I had an idea for something that I think is highly
>> expressive but also can be implemented efficiently.
>> The idea is that the context of triple can be,  not a name,  but a
>> collection of tags that work like tags on delicious,  flickr,   
>> etc.  Tags
>> are going to be namespaced like RDF properties,  of course,  but  
>> they could
>> have meanings like:
>> #ImportedFromDBpedia3.3
>> #StoredInPhysicalPartition7
>> #ConfidentialSecurityLevel
>> #NotTrue
>> #InTheStarTrekUniverse
>> #UsedInProjectX
>> #UsedInProjectY
>> #VerifiedToBeTrue
>> #HypothesisToBeTested
>> Individually I call these "Context Tags",  and the set of them that  
>> is
>> associated with a triple is a "Context Set".
>
> I see all of those as being Named Graphs.
>
>> Now,  named graphs can be composed from boolean combination of  
>> tags,  such
>> as
>> AND(#ImportedFromDbPedia3.3,#InTheStarTrekUniverse)
>> NOT(#NotTrue)
>> AND 
>> (NOT(#ConfidentialSecurityLevel),OR(#UsedInProjectX,#UsedInProjectY))
>
> ...and these as more Named Graphs, or at least graphs that are derived
> from those in the underlying data store. I tend to refer to these as
> "synthetic graphs". Most SPARQL implementations have the concept of at
> least one synthetic graph: the union of all Named Graphs in the
> system. But as I alluded to in a recent posting [1], there are many
> other ways that these graphs could be derived. Rather than building
> them into the implementation, they could be described and using a
> simple domain specific language. So I think Named Graphs plus graph
> algebra gives you much of what you want.
>
> Cheers,
>
> L.
>
> [1]. http://www.ldodds.com/blog/2009/11/managing-rdf-using-named-graphs/
>
>
> -- 
> Leigh Dodds
> Programme Manager, Talis Platform
> Talis
> leigh.dodds@talis.com
> http://www.talis.com
>
>

-- 
Jeni Tennison
http://www.jenitennison.com
Received on Monday, 18 January 2010 19:57:16 UTC

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