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Re: [prov-o] How to express Involvement as as an "Abstract" class in OWL

From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Date: Thu, 23 Feb 2012 13:59:53 +0000
Message-ID: <EMEW3|1b9e4eaf301e1775a97d8bcef47c9492o1MDxu08L.Moreau|ecs.soton.ac.uk|4F464659.1090405@ecs.soton.ac.uk>
To: Khalid Belhajjame <Khalid.Belhajjame@cs.man.ac.uk>
CC: public-prov-wg@w3.org
Hi Khalid,

I think the OWL-RL requirement that we cannot have a union in the domain 
of a property
forces us to define a class for this union, but it is the very presence 
of this new class that
allows us to express descriptions that are not aligned with the DM.


On 02/23/2012 01:09 PM, Khalid Belhajjame wrote:
> Hi Luc,
> I think your approach works, I don't see any issue for the moment.
> Perhaps the only downside, which I don't think is that problematic, is 
> that we need to add extra sub-properties that (re)define the 
> properties defined at the level of the class that we cannot 
> instanciate, e.g., provs:entity which has as a domain 
> provs:EntityInvolvement, need to be redefined at the level of the 
> descendent classes that can be instanciated, e.g., prov:usedEntity for 
> prov:Usage.
> Thanks, khalid
> On 23/02/2012 12:41, Luc Moreau wrote:
>> Hi Khalid,
>> Just trying to expand on this idea:
>> :a1 a prov:Activity
>>   prov:used :e1
>>   prov:usage [a Usage
>>                       prov:usedEntity  :e1
>>                       prov:usedTime t]
>> Then, in prov-s (s for structure)
>>  prov:usedEntity subPropertyOf provs:entity
>>  prov:Usage subclassOf provs:EntityInvolvement
>>  prov:usedTime subRelationOf provs:hadTemporalExtent
>>  provs:entity domain: provs:EntityInvolvement
>>                      range  prov:Entity
>>   prov:usage subrelationOf provs:qualified
>>   provs:qualified domain: provs:Element
>>                            range: provs:Involvement
>>   prov:Activity subclassOf provs:Element
>>   prov:Entity subclassOf provs:Element
>> All the patterns are preserved. The concern about Involvement not
>> being abstract has disappeared. In prov, you can't express instance
>> of involvement, its' only in provs you can.
>> Thoughts?
>> Luc
>> On 02/23/2012 11:52 AM, Khalid Belhajjame wrote:
>>> On 23/02/2012 11:44, Luc Moreau wrote:
>>>> Hi Khalid,
>>>> Can the structure and vocabulary be in separate ontologies?
>>>> This would allow the vocabulary to be kept as simple as possible, 
>>>> as close to the data model as possible.
>>>> I don't think it would be a requirement for the structure-part to 
>>>> be OWL-RL compatible.
>>> I haven't thought about it hard, but I guess one of the issue we may 
>>> need to solve in that case is the properties that are common to the 
>>> sub-classes and defined at the level of the "abstract" class. For 
>>> example, EntityInvolvement has the property "entity" that is used to 
>>> specify the involved entity. If we opt for the solution you are 
>>> suggesting, then we will need to define such property for every 
>>> descendent class that can be instantiated.
>>> Khalid
>>>> Thoughts?
>>>> Luc
>>>> On 02/23/2012 10:59 AM, Khalid Belhajjame wrote:
>>>>> In the prov-o ontology, the involvement class is used as a mean 
>>>>> for giving a structure to the ontology. There are different types 
>>>>> of involvement, e.g., Usage, Generation and Derivation. However, 
>>>>> as it is, the ontology allows specifying an instance of 
>>>>> Involvement that is not an instance of any of its sub-classes. 
>>>>> That should not be allowed.
>>>>> In OWL, the notion of abstract class does not exist, however, one 
>>>>> thing that can be done to avoid the above issue is to ass a 
>>>>> constraint specifying that Involvement is equivalent to the class 
>>>>> constructed by unionining its sub-class. While this solution is 
>>>>> plausible, I am not sure if this constraint is OWL-RL compatible. 
>>>>> I suspect so, but we need a confirmation.
>>>>> The same problem occurs in other cases in the ontology where the 
>>>>> classes have been introduced for shaping the structure of the 
>>>>> ontology, for example Element, ActivityInvolvement, 
>>>>> EntityInvolvement and AgentInvolvement.
>>>>> khalid

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 Thursday, 23 February 2012 14:00:21 UTC

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