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Re: Proposal for restructuring PROV-DM into core+extensions

From: Graham Klyne <graham.klyne@zoo.ox.ac.uk>
Date: Sat, 12 May 2012 17:11:09 +0100
Message-ID: <4FAE8B9D.1080702@zoo.ox.ac.uk>
To: Jim McCusker <mccusj@rpi.edu>
CC: W3C provenance WG <public-prov-wg@w3.org>
Jim,

The intent was that they all remain normative - not demoted to "note" status.

On 12/05/2012 13:53, Jim McCusker wrote:
> What does it mean for something to be in an extension? This potentially has
> consequences beyond just trying to make the documentation simpler, but can
> in effect demote constructs that we have already voted on being in the
> specification to something like a Note status. The number of items that
> have been identified for exclusion from the core, and the fact that a large
> chunk of them are, as you say, arguably should stay in,

Hardly a "large chunk".  There are only two I excluded that might meet my 
"structural" criteria for staying in (specialization and alternative).  And 
there are two currently in the core that I don't think should be, except they 
don't have a common generalization.

> ... suggests that we
> have kept things that might be extensions to a minimum, and that we
> shouldn't bother trying to separate out what has already been agreed to be
> kept in (often after a lot of work sorting out the details and
> consequences).

It's not a case of "in" or "out" - what I have done is identified those aspects 
that are primarily structural in nature, without which the essential provenance 
structure could not be expressed.  The rest are (substantially) refinements of 
those core ideas.

When I've worked with other complex ontologies, (CIDOC-CRM and FRBR in 
particular) I have found it extremely useful to have the structural core 
elements identified so I can focus my initial understanding on them, then the 
rest of the terms fall into place as needed.  That's the effect I'm trying to 
achieve here.

Maybe the phrasing core vs *extension* isn't helpful - I was following what was 
discussed in the telecon - in my own thinking I tend to see them as 
predominantly "structural" vs "epistemic".  Another phrasing might be 
core/structural and refinement terms.

...

There's another thing I haven't mentioned about my selection:  I think the core 
concepts pass the "test of independent invention" (cf. 
http://www.w3.org/DesignIssues/Principles.html).  I see very close close 
analogues of these core concepts in all the provenance ontologies I've looked 
at, and also in CIDOC CRM (which was proposed as a possible provenance ontology 
in one of the early WG teleconferences).  It;'s not so clear this is true of the 
other terms.

#g
--

  On Sat, May 12, 2012 at 6:13 AM, Graham Klyne<graham.klyne@zoo.ox.ac.uk>wrote:
>
>> Following Thursday's telecon, I've done an initial cut of a proposal for
>> rearranging PROV-DM material:
>>
>> http://www.w3.org/2011/prov/**wiki/ProvDM_Proposal_for_**restructuring<http://www.w3.org/2011/prov/wiki/ProvDM_Proposal_for_restructuring>
>>
>> I've added abstract to the document outline that try to capture the
>> distinction/rationale for the proposed structure.
>>
>> For the most part, I find the distinction between essential structure and
>> epistemic refinement has bene fairly easy to call, but there are,
>> inevitably, a couple of areas where it's not so clear for me.
>>
>> (a) wasInformedBy and wasStartedByActivity - I think these are both
>> instances of an (as yet) unstated parent structure, which one might call
>> "wasInfluencedBy" - i.e. any effect of one activity on another activity.
>>   My choice would be to have this new property in the core, and
>> wasInformedBy and wasStartedByActivity as refinements (i.e.extensions)
>>
>> (b) wasInvalidatedBy - in terms of capturing the essence of a provenance
>> trace, this seems of secondary importance, but it does seem to be the
>> natural counterpart for wasGeneratedBy so I've left it in core for now.
>>
>> (c) entity specializationOf and alternateOf.  These could be argued to be
>> purely structural, but I felt that they aren't essential to representing a
>> provenance trace, and they are sufficiently tricky that I didn't want to
>> risk the potential distraction of including them in the core.
>>
>> In drawing up this proposal, I have tried to focus on reorganizing
>> existing material.  Separately from that, I think there are a number of
>> possible improvements, some of which would be facilitated by the
>> reorganization.
>>
>> I've also included in the core some of the auxilliary material that I
>> think is needed to properly explain the core data model constructs
>> (attributes, values, etc.) and have included it further to the front than
>> in the current document, under "Preliminaries".
>>
>> #g
>>
>>
>
>
Received on Saturday, 12 May 2012 16:13:32 GMT

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