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Re: Changes to prov:Dictionary

From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Date: Wed, 06 Jun 2012 22:05:43 +0100
Message-ID: <EMEW3|367f75a991be35bcf5b892b78c16ef0ao55M5p08L.Moreau|ecs.soton.ac.uk|4FCFC627.7030200@ecs.soton.ac.uk>
To: Timothy Lebo <lebot@rpi.edu>
CC: Stephan Zednik <zednis@rpi.edu>, Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk>, "public-prov-wg@w3.org WG" <public-prov-wg@w3.org>
Hi Tim,

See below

On 06/06/12 21:26, Timothy Lebo wrote:
> Luc,
>
> On Jun 6, 2012, at 2:36 PM, Luc Moreau wrote:
>
>>
>> Hi all,
>>
>> I dont understand this discussion.
>>
>> See example 50
>> http://dvcs.w3.org/hg/prov/raw-file/default/model/prov-dm.html#example_50
>
> http://aquarius.tw.rpi.edu/prov-wg/prov-o#derivedByInsertionFrom
> has a prov-o example very similar to #example_50.

>
>> We explicit list the contents of a dictionary after some insertion.
>
> I agree with this example, what does it show that is wrong with prov-o?
>
>

I never claimed anything was wrong with prov-o.

Do you agree with the conclusions drawn in example 50, where the *exact* 
contents
of the dictionaries are listed?


>>
>> Definition 38 in prov-constraints define membership
>> http://dvcs.w3.org/hg/prov/raw-file/default/model/prov-constraints.html#membership-as-insertion 
>>
>
> Great.
>
>>
>> Disallowing complete membership seems to go against the definition of 
>> insertion.
>
> How so?
> "Insertion is a derivation that transforms a dictionary into another, 
> by insertion of one or more key-entity pairs."
>
>
>
>> Are you suggesting that we don't exactly know what is being inserted 
>> in a dictionary?
>
> No, we know _exactly_ what is inserted into the dictionary. They 
> inserted KeyValuePairs are listed right in the assertion.
>


>
> What we're saying is that for any prov:Dictionary and for any N known 
> members, there is no way to know if that prov:Dictionary only has N 
> members, or if there are more.

So, if I understand you correctly,

The following is fine:

memberOf(d1, {("k1", e1), ("k2", e2)} )  //d1 has the following pairs as 
members: ("k1", e1), ("k2", e2), and may contain others.


The following should not be allowed.

memberOf(d2, {("k1", e1), ("k2", e2)}, true)  //d2 exactly has the 
following pairs as members: ("k1", e1), ("k2", e2), and does not contain 
any other.

The following is fine:

entity(d0,[prov:type='prov:EmptyDictionary'])
derivedByInsertionFrom(d3, d0, {("k1", e1), ("k2", e2)})   //d3 exactly 
has the following pairs as members: ("k1", e1), ("k2", e2), and does not 
contain any other.

But this latter expression is exactly
memberOf(d3, {("k1", e1), ("k2", e2)}, true)
as per constraint 38.

So, if we reject one expression and its interpretation,  shouldn't we 
also reject the other?

>
> Membership is alive and healthy in this last PROV-O update announced 
> in this thread.

Uuhh?

>
> What is being proposed is that the class prov:CompleteDictionary (and 
> DM's optional "complete" attribute)  be removed from PROV.

It still allows us to express complete membership, as per d3 above.

I still don't understand. We can remove it, it doesn't seem to change 
anything in the model,
it just  disallows some syntactic sugar.

Luc

>
>
> -Tim
>
>
>
>>
>>
>>
>> Professor Luc Moreau
>> Electronics and Computer Science
>> University of Southampton
>> Southampton SO17 1BJ
>> United Kingdom
>>
>> On 6 Jun 2012, at 17:05, "Stephan Zednik" <zednis@rpi.edu 
>> <mailto:zednis@rpi.edu>> wrote:
>>
>>>
>>> On Jun 6, 2012, at 10:57 AM, Timothy Lebo wrote:
>>>
>>>> Stian,
>>>>
>>>> On Jun 6, 2012, at 10:39 AM, Stian Soiland-Reyes wrote:
>>>>
>>>>> Without EmptyCollection or CompleteMembership the
>>>>> collections/dictionaries are of almost no worth to my use cases,
>>>>
>>>> EmptyCollection remains in the latest PROV-O (so that is not an issue).
>>>>
>>>> It was CompleteMembership that got the ax (this is the topic at hand).
>>>>
>>>> Regarding your use cases, I think it's important to cite Graham's 
>>>> points about uses cases for standards:
>>>> http://www.w3.org/mid/4FCEFCB0.4090100@zoo.ox.ac.uk
>>>
>>> +1 to the relevance of Graham's point about scope creep and system 
>>> use cases vs. coverage/scope of a standard.
>>>
>>>>
>>>>
>>>>
>>>>> as
>>>>> all I can say then is that "some of the members are X, Y and Z" - but
>>>>> there might also be A, B and C.
>>>
>>> Are you specifically worried about the possibility that other 
>>> members may be asserted at a later time by someone else?  If this is 
>>> an issue than perhaps you could use a system-specific extension of 
>>> prov:Collection which utilizes a terminated ordered list.
>>>
>>> I must reiterate my agreement with Graham's point above that this 
>>> need from this use case should not become a requirement for all 
>>> collections defined in the standard.
>>>
>>>>> In Taverna workflows, all collections
>>>>> are closed (unless you export provenance before a workflow has
>>>>> finished). It is important to know that ALL these genes - and no other
>>>>> genes - came back. Just saying "some of these came back" is of less
>>>>> value.
>>>>
>>>> Would this use case be handled if Taverna instead leveraged the 
>>>> "additional attributes" that DM already provides?
>>>>
>>>> memberOf(id; c, {(key_1, e_1), ..., (key_n, e_n)}, cplt, attrs)
>>>>
>>>> perhaps a property taverna:isComplete or class 
>>>> taverna:CompleteDictionary ?
>>>
>>> Even if this attribute was added to the prov or an extension of 
>>> prov, it does not enforce the closed-world membership that Stian 
>>> would like to have.
>>>
>>> No attribute or class specialization will resolve the issue of 
>>> trying to enforce CWA in RDF.
>>>
>>>>
>>>>>
>>>>>
>>>>> I understand that in RDF if we don't use rdf:List, then statements of
>>>>> such completeness are still fairly vague as the lists are not
>>>>> terminated and additional tuples could be adding
>>>>> members/insertions/removals.
>>>>
>>>> If this can't be handled soundly and properly in PROV-O and OWA, 
>>>> then I don't think we should try (or, fake it).
>>>
>>> +1
>>>
>>> I think in general the idea of 'completeness' is incompatible with 
>>> OWA and should not be addressed in PROV-O.
>>>
>>> --Stephan
>>>
>>>>
>>>>>
>>>>> However when I make a provenance export of a workflow run, I would
>>>>> want to also say something like "These are all the workflow processes
>>>>> that ran, and these are all the entities that were created".
>>>>
>>>>
>>>>
>>>>> But
>>>>> perhaps a more general completeness-claim for an account/bundle is out
>>>>> of scope for PROV.
>>>>
>>>> That seems to be the predominant perspective, as people have 
>>>> indicated in various email threads and tracker issues.
>>>> With the use of a custom attribute and type ( taverna:isComplete or 
>>>> class taverna:CompleteDictionary ), can you accept removing the 
>>>> special optional parameter on DM's memberOf?
>>>>
>>>>>
>>>>>
>>>>> However, I still don't undertstand what is the problem with saying
>>>>> something is an empty collection.
>>>>
>>>> Not an issue. EmptyDictionary is still in there :-)
>>>>
>>>> Thanks!
>>>> Tim
>>>>
>>>>>
>>>>> On Wed, Jun 6, 2012 at 2:49 PM, Luc Moreau 
>>>>> <L.Moreau@ecs.soton.ac.uk <mailto:L.Moreau@ecs.soton.ac.uk>> wrote:
>>>>>>
>>>>>> Hi Tim,
>>>>>>
>>>>>> It's specifically your last point. Being to express whether 
>>>>>> membership was complete
>>>>>> was a request from Stian and Paolo I believe.
>>>>>>
>>>>>> Luc
>>>>>>
>>>>>>
>>>>>> On 06/06/2012 02:31 PM, Timothy Lebo wrote:
>>>>>>
>>>>>> Luc,
>>>>>>
>>>>>> On Jun 6, 2012, at 12:48 AM, Luc Moreau wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>> On 5 Jun 2012, at 23:18, "Timothy Lebo" <lebot@rpi.edu 
>>>>>> <mailto:lebot@rpi.edu>> wrote:
>>>>>>
>>>>>> prov-wg (and prov-dm editors),
>>>>>>
>>>>>> I've reviewed all of the materials (that I can find) regarding 
>>>>>> collective concerns about prov:Dictionary, and
>>>>>> have committed changes to the latest PROV-O owl and html to 
>>>>>> address those concerns:
>>>>>>
>>>>>> * https://dvcs.w3.org/hg/prov/raw-file/default/ontology/Overview.html
>>>>>> * 
>>>>>> http://dvcs.w3.org/hg/prov/raw-file/default/ontology/ProvenanceOntology.owl
>>>>>>
>>>>>> The changes are summarized here:
>>>>>>
>>>>>> http://www.w3.org/2011/prov/wiki/index.php?title=Eg-34-us-supreme-court-membership&oldid=7905#PROV-O_changes_made.2C_inspired_by_this_example 
>>>>>> <http://www.w3.org/2011/prov/wiki/index.php?title=Eg-34-us-supreme-court-membership&oldid=7905#PROV-O_changes_made.2C_inspired_by_this_example>
>>>>>>
>>>>>> and repeated here:
>>>>>>
>>>>>>  Added class prov:Collection, as subclass of Entity
>>>>>> Added property prov:hadMember domain prov:Collection range 
>>>>>> prov:Entity.
>>>>>>
>>>>>> This supports both generic "simple set" prov:Collection and 
>>>>>> prov:Dictionary.
>>>>>>
>>>>>> Made KeyValuePair a subclass of Entity
>>>>>>
>>>>>> this follows from Set Collection :c prov:hadMember :my_member and 
>>>>>> the definition of Collection "A collection is an entity that has 
>>>>>> some members. The members are themselves entities").
>>>>>>
>>>>>> Renamed prov:membership to prov:qualifiedMembership to follow 
>>>>>> qualification pattern naming.
>>>>>> prov:Membership became subclass of prov:EntityInvolvement 
>>>>>> (though, it could become subclass of 
>>>>>> prov:KeyValuePairInvolvement, itself a subclass of 
>>>>>> prov:EntityInvolvement. But we'll try to simplify and reuse 
>>>>>> prov:entity)
>>>>>> prov:member renamed to prov:pair and became a subproperty of 
>>>>>> prov:involvee
>>>>>> Added property chain (qualifiedMembership o prov:pair) 
>>>>>> rdfs:subClassOf prov:hadMember
>>>>>> Added prov:removed domain prov:Removal range prov:KeyValuePair
>>>>>> Removed prov:CompleteDictionary from DM and PROV-O.
>>>>>>
>>>>>> Why?
>>>>>> Luc
>>>>>>
>>>>>>
>>>>>>
>>>>>> What in particular would you like to discuss.
>>>>>> As I said, this reflects a response to many concerns that have 
>>>>>> been raised by many people in many forms.
>>>>>> In an effort to maintain focus and to make progress, I recommend 
>>>>>> that these points, the latest prov-dm, and the latest prov-o 
>>>>>> update serve as the basis for these discussions.
>>>>>>
>>>>>> -Tim
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> You'll notice the prov-o modeling of Dictionaries is not 
>>>>>> consistent with latest prov-dm.
>>>>>>
>>>>>> The prov-o team would like to ask the prov-dm editors to 
>>>>>> reconsider how collections and dictionaries are defined, so that 
>>>>>> they reflect the latest prov-o modeling of the PROV concepts.
>>>>>>
>>>>>> Regards,
>>>>>> Tim Lebo
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> cc tracker ISSUE-374 ISSUE-391
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> 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 <mailto:l.moreau@ecs.soton.ac.uk>
>>>>>> United Kingdom http://www.ecs.soton.ac.uk/~lavm 
>>>>>> <http://www.ecs.soton.ac.uk/%7Elavm>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Stian Soiland-Reyes, myGrid team
>>>>> School of Computer Science
>>>>> The University of Manchester
>>>>>
>>>>>
>>>>
>>>
>
Received on Wednesday, 6 June 2012 21:06:22 UTC

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