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Re: PROV-ISSUE-145 (Tlebo): qualified identifiers may not work well with named graphs [Data Model]

From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Date: Mon, 07 Nov 2011 08:57:18 +0000
Message-ID: <EMEW3|8a7fad0b350fd0d8bd763a403d83098cnA68vM08L.Moreau|ecs.soton.ac.uk|4EB79D6E.3090704@ecs.soton.ac.uk>
To: Tim Lebo <lebot@rpi.edu>
CC: Provenance Working Group WG <public-prov-wg@w3.org>
Hi Tim,

Resources are identified by a URI. It has been suggested that 
perspectives we
take over a given resource, i.e. entities, may use the resource URI as 
their own
identifier (provided this does not result in clash names, as suggested 
in last section
of prov-dm document).

Hence, two different entities could be asserted by two different 
asserters in different accounts,
and both may have chosen the same URI to identify them.

If we want to avoid this, then it must be a requirement that new URIs 
are minted for all
entities. But I thought the WG wanted to move away for that, since it 
prevents lightweight assertions
of provenance.

So, the minting burden, i think, is put at the level of accounts.
BTW, prov-dm is currently not suggesting that, since it says that 
account identifiers are also scoped,
but I think this is not good.

Luc

On 11/06/2011 11:49 PM, Tim Lebo wrote:
> Hi, Luc!
>
> Sent from my iPhone
>
> On Nov 6, 2011, at 17:44, Luc Moreau<L.Moreau@ecs.soton.ac.uk>  wrote:
>
>    
>> Hi Tim,
>>
>> We need to explore this in detail.
>> To me, it is crucial to be able to assert that entity e1 in account acc1 is complementOf entity e2 in acc2.
>>      
> Absolutely.
>
>    
>> How do you propose doing this?
>>      
> Would the one triple
>
> :e1 prov:wasComplementOf :e2 .
>
> work? This would stand independent of what account the entities are in -- which gets to the point I was making that the asserter needs to make distinct URIs and not depend on some account-based scoping mechanism to establish its identity.
>
> Perhaps I am misinterpreting DM again from a "too RDF" perspective like the literal versus URI discussions earlier today.
>
> Best,
> Tim
>
>    
>>
>>
>> Professor Luc Moreau
>> Electronics and Computer Science
>> University of Southampton
>> Southampton SO17 1BJ
>> United Kingdom
>>
>> On 6 Nov 2011, at 21:24, "Timothy Lebo"<lebot@rpi.edu>  wrote:
>>
>>      
>>> By "appropriately scoped", I mean "predefined, consciously selected; URIs".
>>>
>>> the note "refer to an identifier in the scope of a given account" sounds like we are going to permit lazy naming that can be computed in the future, which current named graph implementations do not support.
>>>
>>> -Tim
>>>
>>>
>>>
>>> On Nov 6, 2011, at 2:32 AM, Luc Moreau wrote:
>>>
>>>        
>>>> Hi Tim,
>>>>
>>>> What do you mean by appropriately scoped?
>>>>
>>>> Luc
>>>>
>>>>
>>>>
>>>> I propose that we require the asserters to define appropriately-scoped URIs for their identifiers. Letting them be lazy up front will cause headaches when actually trying to use it.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>          
>>>        
>>      

-- 
Professor Luc Moreau
Electronics and Computer Science   tel:   +44 23 8059 4487
University of Southampton          fax:   +44 23 8059 2865
Southampton SO17 1BJ               email: l.moreau@ecs.soton.ac.uk
United Kingdom                     http://www.ecs.soton.ac.uk/~lavm
Received on Monday, 7 November 2011 08:57:56 UTC

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