W3C home > Mailing lists > Public > public-gld-comments@w3.org > March 2013

Re: Feedback to the LC of the Organization Ontology from the Prov WG

From: Jun Zhao <jun.zhao@zoo.ox.ac.uk>
Date: Fri, 22 Mar 2013 11:31:27 +0000
Message-ID: <514C410F.9000808@zoo.ox.ac.uk>
To: Dave Reynolds <dave.e.reynolds@gmail.com>
CC: public-gld-comments@w3.org, Provenance Working Group WG <public-prov-wg@w3.org>
Dear Dave,

Thank you very much for your response to our feedback to the LC of the 
Organization Ontology. We took a look at your response and this is to 
confirm that we are happy with them.

In case any communication confusion happens again, please feel free to 
forward the response to any more appropriate mailing lists or advise me 
any other lists that I should send the response to.

Regards,

Jun (on behalf of the PROV WG)

On 2/21/13 4:17 PM, Dave Reynolds wrote:
> Dear Jun and Provenance Working group,
>
> Thank you again for your helpful and thoughtful comments on the
> Organization Ontology and its use of PROV-O terms.
>
> You offered three comments:
>   1. that prov:wasDerivedFrom should be explicitly or implicitly
>      asserted
>   2. that we should check that our intended use of PROV-O would not
>      lead to any violation of the PROV semantic constraints [1]
>   3. that we might consider use of PROV invalidation terms
>
> 1. prov:wasDerivedFrom
>
> We agree with your recommendation that a prov:wasDerivedFrom
> relationship should exist between the org:originalOrganization and
> org:resultedFrom Organization of an org:changeEvent. We have adopted
> your suggestion of expressing this by means of a property chain axiom
> and have added this axiom to the ontology and added an explanatory
> example as part of informative section [2].
>
> 2. Semantic Constraints
>
> We have examined the semantic constraints expressed in [1]. We see no
> conflict between those and intended usage of ORG. For those terms in
> ORG which relate to PROV-O terms we see no semantic constraints which
> would limit usage of the ORG terms themselves. Applications of ORG
> which make direct use of additional PROV-O terms (e.g. to describe the
> time period of a change event) should naturally take the semantic
> constraints on those terms into account. We have included a mention of
> this in the informative section [2].
>
> 3. PROV invalidation terms
>
> Thank you for bringing this part of PROV to our attention. There may
> well be applications of ORG which also wish to express such
> invalidation information in which case they should be, and are, free
> to use the relevant PROV-O terms. However, we do not have particular
> use cases in this area and feel the existing references to PROV-O are
> sufficient to allow ORG users to decide whether additional parts of
> PROV-O, like this, are relevant to their usage.
>
> We would be grateful if you could confirm if you are content with
> these responses.
>
> Thanks again for your feedback, much appreciated.
>
> Dave Reynolds (on behalf of GLD working group)
>
> [1] http://www.w3.org/TR/2012/WD-prov-constraints-20120911/
> [2]
> https://dvcs.w3.org/hg/gld/raw-file/default/org/index.html#organizational_history
>
>
> On 25/11/12 09:43, Jun Zhao wrote:
>> Dear Organization Ontology Editors,
>>
>> The PROV WG reviewed the part of the document about extension to PROV.
>> Generally speaking we agree with your following extensions:
>>
>>   - org:originalOrganization as a subproperty of prov:used,
>>   - org:resultedFrom as a subproperty of prov:wasGeneratedBy
>>   - org:ChangeEvent as a subclass of prov:Activity
>>
>> In addition, we would like to draw your attention to the concept of
>> derivation [1] in PROV, which refers to a transformation of an entity
>> into another, an update of an entity resulting in a new one, or the
>> construction of a new entity based on a pre-existing entity. Based on
>> some general knowledge, one might expect that a new organization should
>> be a derivation of the old one, by some sort of transformation or update
>> or simply setting up a new entity. But does this indeed make sense with
>> the use cases that you consider?
>>
>> This is a strong albeit useful assertion, enabling you to trace the
>> history of an organization. However, the semantics of the PROV model
>> does not let you infer this relationship by the combination of
>> generation and usage, i.e.,  from the following triples:
>>
>> ex:o2  org:resultedFrom          ex:a1
>> ex:a1  org:originalOrganization  ex:o1
>>
>> The PROV model regards ex:o1 and ex:o2 as totally unrelated, unless
>> their relationship is explicitly stated otherwise. If the definition of
>> derivation does fit your use case,  making use of this relationship in
>> your ontology will make it much more in line with the upcoming
>> provenance recommendation. So it is a matter to have a think about what
>> you intend to achieve by using the prov:used and prov:wasGeneratedBy
>> properties. If you want to include derivation in your ontology, then we
>> make the following to suggestions:
>>
>> 1. We RECOMMEND that ex:o2 prov:wasDerivedFrom ex:o1 be explicitly
>> asserted. (or a subproperty in the org: namespace)
>> 2. Alternatively, you could add a property chain
>>        org:resultedFrom followed by org:originalOrganization =>
>> prov:WasDerivedFrom
>>
>>
>> The second point is that the PROV model comes with a set of implicit
>> semantics constraints (in its constraint document [2]). Although these
>> constraints are not reflected in the PROV-O, we expect that a provenance
>> validator, compliant with  this document, will validate provenance
>> statements on the Web. Therefore, it might be worthwhile to take a pause
>> and think whether the intention behind your ontology might lead to any
>> violation to relevant constraints.
>>
>> For example, the generation-precedes-usage constraint [3] requires that
>> the event when a new organization was generated must precede the event
>> when the same organization was used in the process of generating another
>> organization.
>>
>>
>> Finally, we would also like to bring your attention to the concept of
>> invalidation. In the PROV data model we say that an entity can have a
>> lifetime. And the invalidation is the start of the destruction,
>> cessation, or expiry of an existing entity by an activity [4].
>>
>> If this concept is adopted in the Organization Ontology, then you will
>> be able to specify more precisely that the cease-to-exist of the old
>> organization when a new organization was built up. Might this be helpful
>> to your use cases?
>>
>> Please be aware that by using this concept, there are several related
>> constraints to bear in mind. An example is the
>> usage-precedes-invalidation constraint [5], which means that the event
>> when an old organization ceased to exist must follow the event when it
>> was used in the org:ChangeEvent activity.
>>
>> We, the WG as a whole, will be happy to help you with any other issue
>> related to PROV.
>>
>> Hope this helps.
>>
>> Jun, on behalf of the PROV WG
>>
>> [1] http://www.w3.org/TR/prov-dm/#term-Derivation
>> [2] http://www.w3.org/TR/2012/WD-prov-constraints-20120911/
>> [3]
>> http://www.w3.org/TR/2012/WD-prov-constraints-20120911/#generation-precedes-usage
>>
>>
>> [4] http://www.w3.org/TR/prov-dm/#term-Invalidation
>> [5]
>> http://www.w3.org/TR/2012/WD-prov-constraints-20120911/#usage-precedes-invalidation
>>
>>
>>
>

-- 
Jun Zhao, PhD
Department of Zoology
University of Oxford
Tinbergen Building, South Parks Road
Oxford, OX1 3PS, UK
Received on Friday, 22 March 2013 11:31:54 GMT

This archive was generated by hypermail 2.3.1 : Friday, 22 March 2013 11:31:55 GMT