- From: Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk>
- Date: Wed, 2 Nov 2011 12:22:15 +0000
- To: Luc Moreau <l.moreau@ecs.soton.ac.uk>
- Cc: W3C provenance WG <public-prov-wg@w3.org>
- Message-ID: <CAPRnXtkaQ+4v5BFNQzrB1em_DTZcGN72y8gknSvjPn1s4whs5w@mail.gmail.com>
+1 to both proposals On Oct 30, 2011 5:57 PM, "Luc Moreau" <l.moreau@ecs.soton.ac.uk> wrote: > > > > > In the interest of simplification, we would like to make the following > proposal about attributes in prov-dm. > > Proposal 1: attributes are a necessary part of prov-dm. Attribute-value > pairs can be optionally > included in Entity Expressions and Activity Expressions. > > The document will justify their presence along the following lines > (text to be worked on, suggestions welcome). For inter-operability > purpose, it is necessary to be able to describe entities (and > activities), and such descriptions need to be part of the provenance > record, so that queries over such descriptions can be expressed. The > document will not make the distinction between non-characterizing and > characterizing attributes. All attributes will be considered as > describing some facet of the entity. > > Proposal 2: Constraints related to attributes will be dropped. > http://www.w3.org/TR/2011/WD-**prov-dm-20111018/#derivation-**attributes<http://www.w3.org/TR/2011/WD-prov-dm-20111018/#derivation-attributes> > http://www.w3.org/TR/2011/WD-**prov-dm-20111018/#use-**attributes<http://www.w3.org/TR/2011/WD-prov-dm-20111018/#use-attributes> > http://www.w3.org/TR/2011/WD-**prov-dm-20111018/#generation-** > affects-attributes<http://www.w3.org/TR/2011/WD-prov-dm-20111018/#generation-affects-attributes> > > Rationale: a number of issues have been raised against these > constraints. They may or may be fixable. But overall, they seem to > overconstraint the model, for benefits that are unclear. There was no > intent to make them automatically verifiable, for > instance. Furthermore, if it is really crucial for some developers to > express that some attributes depend on others, than prov-dm already > offers a mechanism: simply model these attributes as entities, and their > dependency as derivation. > > A further consequence is that derivation can be made transitive! > (subject of a separate proposal) > > Finally, the semantics team may want to reconsider these constraints and > formalize them properly. > > Cheers, > Luc > > >
Received on Wednesday, 2 November 2011 12:22:55 UTC