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Re: ISSUE-385: hasProvenanceIn: finding a solution

From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Date: Wed, 06 Jun 2012 22:36:33 +0100
Message-ID: <EMEW3|d12dd07a429f0ab2dd2fd158acf31a51o55Mae08L.Moreau|ecs.soton.ac.uk|4FCFCD61.4050801@ecs.soton.ac.uk>
To: public-prov-wg@w3.org
Hi Simon

Response interleaved.

On 06/06/12 16:29, Miles, Simon wrote:
> Hello Luc, all,
> Sorry, just catching up on all the mails on this topic.
> I have a stronger idea of what is being aimed for. In particular, I 
> think the key point I didn't properly account for in replying to the 
> original hasProvenanceIn proposal is that we want this all to work 
> without requiring any reasoning.
> I'm glad we seem agreed that there is a need for alternateOf or 
> specializationOf along with any contextualizationOf/hasProvenanceIn 
> assertion.
> I have three thoughts about the current contextualizationOf specification.
> 1. At least the first example for contextualization has many 
> similarities to the specialization example used in the primer, i.e. a 
> coarse-grained entity has been referred to earlier (in one context) 
> then the distinction between two finer grained versions of the entity 
> is required later (another context), and we use specialization to 
> express how the different granularities relate. I think the difference 
> between the relations might be clarified if we said what kind of thing 
> the "Something" and "another" are in the contextualization definition.

I thought they could be anything we can identify. The example has a 
contextualization for an instance of derivation.
Do you have some suggestion?

> 2. By referring to a bundle as a context, there is the implication 
> that the statements in a single bundle present a single, consistent 
> context. The current DM does not obviously support this, and it could 
> be restrictive.

I didn't mean to imply this. I am not sure what consistency means here.  
What do you think implies it?

> To try to answer my own points, could we say something like the following?
> Contextualization is a relation between an entity and a bundle, 
> asserting that the entity is described in a somehow consistent context 
> in that bundle. It further refers to a perspective on that entity 
> used within that context, i.e. another entity that this entity is an 
> alternate or specialization of. Not every bundle of PROV descriptions 
> necessarily presents a consistent context.

> 3. Why are we assuming that there is only one alternate/generalised 
> entity in the bundle referred to? It happens to be true in the 
> examples, but what if ex:run1 also contained:
>   alternateOf(ex:Bob, ex:Obo)
> Why would the contextualizationOf statement in tool:analysis01 only 
> refer to ex:Bob and not ex:Obo?

In my previous email to Tim, I was giving an example with multiple 
contextualizationOf statements

We could have:

    contextualizationOf(e, ex:Bob, bundle1) // e presents the facet of 
ex:Bob in bundle1
    contextualizationOf(e, ex:Obo, bundle2) // e also presents the facet 
of ex:Obo in bundle2


> I notice a mistake in the first example:
>   specialization(tool:ratedBob2, [perf:rating="bad"])

yes, thanks, this was all messed up.
Hopefully fixed now.

Luc
> thanks,
> Simon
> Dr Simon Miles
> Senior Lecturer, Department of Informatics
> Kings College London, WC2R 2LS, UK
> +44 (0)20 7848 1166
> Provenance: The bridge between experiments and data:
> http://eprints.dcs.kcl.ac.uk/1372/
> ------------------------------------------------------------------------
> *From:* Luc Moreau [l.moreau@ecs.soton.ac.uk]
> *Sent:* 05 June 2012 21:03
> *To:* Timothy Lebo
> *Cc:* W3C provenance WG
> *Subject:* Re: ISSUE-385: hasProvenanceIn: finding a solution
>
> Hi Tim,
>
> I tried to write this up as a separate relation contextualizationOf, 
> see section 1.3 in [1].
> I believe this relation is compatible with your rdf encoding. The only 
> difference, here,
> is that we make this an identifiable thing.
>
>        [
>            a prov:Entity;  prov:ContextualizedEntity;
>            prov:identifier       ex:Bob;
>            prov:inContext     ex:run2;
>        ];
>
> What do you think?
> Luc
>
> [1] 
> http://dvcs.w3.org/hg/prov/raw-file/default/model/working-copy/wd6-contextualization.html
>
> On 04/06/2012 23:25, Timothy Lebo wrote:
>> Luc,
>>
>> (bottom)
>>
>> On Jun 4, 2012, at 5:31 PM, Luc Moreau wrote:
>>
>>> Hi Tim,
>>>
>>> Some comments/questions below.
>>>
>>> On 04/06/2012 13:46, Timothy Lebo wrote:
>>>> Luc,
>>>>
>>>> On Jun 4, 2012, at 5:16 AM, Luc Moreau wrote:
>>>>
>>>>> Hi all,
>>>>>
>>>>> During this diamond jubilee WE, I had the opportunity to think 
>>>>> about Tim and Simon's long emails.
>>>>>
>>>>> I agree with them that we have concepts of alternate and 
>>>>> specialisation, and we want to reuse them.
>>>>>
>>>>> I also came to the conclusion that behind the hasProvenanceIn 
>>>>> relation, what I really wanted was a form of alternate. But not 
>>>>> what Tim or Simon are suggesting.
>>>>>
>>>>> The PROV data model has a shortcoming: the inability to identify 
>>>>> something in some context. That's what I am trying to address here.
>>>>>
>>>>
>>>>
>>>>> 
>>>>
>>>>
>>>>> The interpretation of
>>>>>        alternate(tool:Bob2, ex:Bob,ex:run2)
>>>>> is that tool:Bob2 is the entity that share aspects of ex:bob as 
>>>>> described by ex:run2. *Conceptually*, this could be done by 
>>>>> substituting ex:Bob for tool:Bob2 in ex:run2.
>>>>>
>>>>> I appreciate that what I am describing here is not too distant 
>>>>> from 
>>>>> http://www.w3.org/TR/2011/WD-prov-dm-20111215/#record-complement-of, 
>>>>> which had optional account, and was not received with enthusiasm, 
>>>>> to say the least.
>>>>>
>>>>> Coincidentally, Paul shared this paper
>>>>> http://ceur-ws.org/Vol-614/owled2010_submission_29.pdf which 
>>>>> introduces  rules of the kind
>>>>> /X counts as Y in context C/
>>>>> which bears some resemblance with what I am trying to argue for.
>>>>>
>>>>> So, my proposal is;
>>>>> - drop hasProvenanceIn
>>>>> - drop isTopicIn
>>>>> - allow for the ternary form of alternate
>>>>>
>>>>> Tim and Simon approach by using two binary relations do not offer 
>>>>> the same level of expressivity.
>>>>> The also have a technological bias, as well: they require 
>>>>> querying/reasoning facility.  Therefore,
>>>>> their suggestion is not suitable for a data model supposed to be 
>>>>> technology neutral.
>>>>
>>>>
>>>> A stab at:
>>>>
>>>> bundle tool:analysis01
>>>>      alternate(tool:Bob2, ex:Bob,ex:run2)
>>>> endBundle
>>>>
>>>> in PROV-O:
>>>>
>>>> tool:analysis01 {
>>>>     tool:Bob2
>>>>        prov:alternateOf [  ## The use here of bnode is, for once, 
>>>> actually appropriate :-)
>>>>            a prov:Entity;  prov:ContextualizedEntity;
>>>>            prov:identifier       ex:Bob;   ## The identifier that 
>>>> is used "over there"   Can't use dcterms:identifier b/c that is a 
>>>> rdfs:Literal.
>>>>            prov:inContext     ex:run2;   ## "over there"       
>>>> Could prov:atLocation be reused?
>>>>        ];
>>>> }
>>>>
>>>
>>> Thanks for this, Tim.
>>>
>>> First some questions:
>>> - why a bnode here?
>>
>> bnodes are read "the thing that" and _can_ serve as an existential.
>>
>>> - Can you explain the  dcterms:identifier comment?
>>
>> 1) The value is the identifier used in the other bundle.
>> 2) The rdfs:range of dcterms:identifier is a literal 
>> "http://foo.com", but it is more useful if it is a rdfs:Resource 
>> <http://foo.com>. With the former, we know that we can "try to go 
>> there" to dereference the URI.
>>
>>>
>>> Now, assuming that this rdf encoding expresses what was originally 
>>> suggested, some further questions:
>>> - have we got indeed a ternary alternateOf relation in prov-dm as I 
>>> suggested?
>>
>> Perhaps. The original binary that we now know and love, and a second 
>> ternary that "wraps" a URI and a Bundle (that mentions the URI).
>> The only new things would be:
>>
>> 1) The two new predicates prov:identifier and prov:inContext (perhaps 
>> that should just be called prov:inBundle -- I was swayed too far 
>> towards DCTerms when I chose that this morning).
>> 2) The new rule to unwrap your ternary DM into this RDF structure.
>>
>>
>>> - or have we got some form of ternary relation 
>>> isContextualizationOf(e2,e1,bundle)?
>>
>> Or, just a binary isContextualized(e1,bundle)?
>>
>> And we just stack on an existing alternateOf(e2,e1)...
>>
>>
>> BTW, not really sure where we're going with this.
>> It feels like we're close to wrapping this up, but worried that we're 
>> in some odd local minima.
>>
>> Regards,
>> Tim
>>
>>
>>>
>>> Thanks,
>>> Luc
>>>
>>
Received on Wednesday, 6 June 2012 21:37:08 UTC

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