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Re: PROV-ISSUE-471 (wrong-wasAttributedTo-constraints): wasAttributedTo constraints not sensical [prov-dm-constraints]

From: Graham Klyne <graham.klyne@zoo.ox.ac.uk>
Date: Thu, 06 Sep 2012 11:57:20 +0100
Message-ID: <50488190.7040000@zoo.ox.ac.uk>
To: Luc Moreau <l.moreau@ecs.soton.ac.uk>
CC: Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk>, public-prov-wg@w3.org
I don't have a strong view on the particular case here, but as a general 
principle I think that if there is not a clear, strong consensus then the path 
of less constraint should be chosen.

It's much easier to add constraints to a pattern than to take them away.


On 03/09/2012 17:00, Luc Moreau wrote:
> Hi all,
> It would be good to hear people's view on wasAttributedTo. Should the agent
> necessarily exist before the entity was generated?
> Should we also disallow examples such as:
> wasAttributedTo(painting,Bob,[prov:type="ownership"])
> prov-dm is not precise about this, and we need to formalize some of these
> constraints in in prov-constraints.
> I don't see how we cat prevent types of attribution such as this example,
> without entering in a theory of causality (as Stian suggests).
> wasAttributedTo(painting,Bob,[prov:type="ownership"])
> therefore, I think this example is legal prov-dm.
> Luc
> On 03/09/12 16:33, Stian Soiland-Reyes wrote:
>> On Mon, Sep 3, 2012 at 2:52 PM, Luc Moreau <l.moreau@ecs.soton.ac.uk
>> <mailto:l.moreau@ecs.soton.ac.uk>> wrote:
>> >> I don't agree with that. First of all, why has the attribution need to
>> >> have anything to do with the invalidation of an entity? If you
>> >> contribute to an entity, all of that has to happen *before* the entity
>> >> is generated. It does not matter what happens after that.
>> > Why should this be *before* the entity exist?
>> >
>> > I believe one can use attribution as follows:
>> >
>> I disagree.
>> The DM spec (my highlights):
>> Attribution^ ◊ <http://www.w3.org/TR/prov-dm/#concept-attribution> is the
>> ascribingof an entity to an agent.
>> When an entity e is attributedto agent ag, entity e was generatedby some
>> unspecified activity that in turn was associatedto agent ag. Thus, this
>> relation is useful when the activity is not known, or irrelevant.
>> An attribution^ ◊ <http://www.w3.org/TR/prov-dm/#dfn-wasattributedto>
>> relation, written wasAttributedTo(id; e, ag, attrs) in PROV-N, has:
>> * id: an /optional/ identifier for the relation;
>> * entity: an entity identifier (e);
>> * agent: the identifier (ag) of the agent whom the entity is
>> ascribed to, and therefore bears some responsibility for its
>> existence;
>> * attributes: an /optional/ set (attrs) of attribute-value pairs
>> representing additional information about this attribution.
>> Although attribute (v)
>> <http://www.oed.com/view/Entry/12933?rskey=xWNM2z&result=3&isAdvanced=false#eid>
>> in the wider sense does cover ownership:
>> *a.* To assign, bestow, give, concede, yield /to/ any one, as
>> his right (property, title, authority, worship,
>> honour)./arch./ or /Obs.
>> (..)
>> /*3.* To ascribe /to/ as belonging or proper; to consider or
>> view as belonging or appropriate /to/.
>> the DM highlights "ascribe", as in:
>> *6.* To ascribe, impute, or refer, as an effect /to/ the cause;
>> to reckon as a consequence of.
>> *7.*To ascribe/to/an author as his work.
>> This narrower understanding of 'ascribe' and 'attribute' was what I had
>> understood we are using, as we have not talked about ownership as a kind of
>> attribution before. We have been talking about a kind of "why" or "who" made
>> something appear - a book was written by an author, a car was manufactured by
>> a factory, a law was passed by its parliament. There are many other
>> definitions on "ascribe" and "attribute" that I likewise don't think cover our
>> intention with wasAttributedTo, like: /ascribe great importance to or To
>> ascribe as a quality or ‘attribute’ belonging./
>> If I own an old and dangerous car, I am not responsible for why it /exists/,
>> the car manufacturer is. I might bear responsibility for why it has not yet
>> been /invalidated/ as it is not road worthy, but that has to do with potential
>> future actions, intentions and plans, and I don't see how /wasAttibutedTo/ in
>> PROV would be suitable for that.
>> We have said that PROV is provenance about the past. Describing that kind of
>> ownership would to me simply be an attribute on the entity, just like it's
>> location, colour, road worthiness status, insurance status, who has access to
>> the car keys, etc. Ownership would not in my mind imply an activity (the
>> "owning" activity? "purchasing"?), just like having the colour red does not
>> imply a "being red" activity. This is about entity vs activity, state vs. change.
>> If you want to broaden the definition of /wasAttributedTo/ to cover mere
>> 'ownership' kind of attribution, I think we need to add clear examples that
>> show the value of this and guides the understanding of PROV-DM, and possibly
>> reconsider the implied activity. I don't remember us discussing this at a WG
>> level.
>> --
>> Stian Soiland-Reyes, myGrid team
>> School of Computer Science
>> The University of Manchester
Received on Thursday, 6 September 2012 11:46:49 UTC

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