Re: prov-dm attributes: two proposals to vote on (deadline Wednesday midnight GMT)

+1 on Proposal 1.
No comment on Proposal 2.

On 10/30/11 10:54 AM, Luc Moreau wrote:
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> 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/#use-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
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