- From: Jun Zhao <jun.zhao@zoo.ox.ac.uk>
- Date: Sun, 25 Nov 2012 09:44:24 +0000
- To: pgroth@gmail.com
- CC: Provenance Working Group WG <public-prov-wg@w3.org>
Thanks Paul, and Luc for his offline support. The comments are now sent back to public-gld-comments@w3.org. Many thanks! -- Jun On 11/23/12 11:44 AM, Paul Groth wrote: > I'm fine with this. > > Paul > > > On Fri, Nov 23, 2012 at 10:22 AM, Jun Zhao <jun.zhao@zoo.ox.ac.uk> wrote: > >> Dear all, >> >> Please find below the draft response that Luc and I prepared for the >> last call for comments by the eGov WG regards to the Organization >> Ontology (http://www.w3.org/News/2012.html#entry-9606). >> >> It will become the group response unless we hear objections by Saturday >> Midnight GMT, November 24th. >> >> Many thanks! >> >> -- Jun >> >> >> >> ==================================================================================== >> >> 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 >> >> >> >> >
Received on Sunday, 25 November 2012 09:44:47 UTC