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Re: Primer first draft for review

From: Graham Klyne <GK@ninebynine.org>
Date: Thu, 17 Nov 2011 10:30:14 +0000
Message-ID: <4EC4E236.5040405@ninebynine.org>
To: Simon Miles <simon.miles@kcl.ac.uk>
CC: Provenance Working Group WG <public-prov-wg@w3.org>
On 15/11/2011 14:06, Simon Miles wrote:
 > The first draft of the primer document is ready for the WG to read and
 > start raising issues against. It would be particularly helpful to know
 > if the general approach/structure is one that makes sense to others.

Reviewing: http://dvcs.w3.org/hg/prov/raw-file/default/primer/Primer.html

Generally, I think this document is very nicely done.  The text is crisp and to 
the point, and the examples are well chosen and well-introduced.  I recognize 
there's more to do, but it's a great start.  I think it's probably worth pushing 
for an early FPWD because I think it well help external reviewers to understand 
the more technical aspects of the model.  It helped me :)

What follows are some relatively minor comments...

...

1. Introduction

Para 1: the primer is not *only* about PROV-DM; it is also about representation 
in RDF using PROV-O-defined terms.  The examples cannot be derived from PROV-DM 
alone.

2.1 Entities

I think this doesn't really capture the relationship between entities and things 
that may change, which is a key motivator for introducing the notion of 
"Entities".  Cf. 
http://dvcs.w3.org/hg/prov/raw-file/tip/paq/provenance-access.html#provenance--entities-and-resources 
for possible adaptable text (though in this context you may prefer to avoid the 
dependence on Web resources.)

Properties/attributes used interchangeably: maybe just use "attributes"?

2.2 Activities

"While entities are static aspects in the world" - I think it's not the "static" 
aspect that's key here.  Philosophically, this is the endurant/perdurant 
(continuant/occurrent) distinction, but that language probably doesn't help 
here.  Instead of static/dynamic, suggest instantaneous/ongoing.

2.7 Complementarity

While I personally think the notion of complementarity described here is the 
more useful one, I don't think it agrees with the current PROV-DM 
(http://dvcs.w3.org/hg/prov/raw-file/tip/model/ProvenanceModel.html#record-complement-of).

(What you describe here might be termed "characterizationOf" (of "viewOf"), 
which notion I see as being foundational; to the way entities are related to 
things.)

2.8 Derivation

I find it is relatively hard to extract the intended meaning of the different 
derivation terms from this.  I think expanding the final paragraph to state the 
aspect illustrated by the referenced examples would help.  e.g.

"In PROV-DM terms, we say that the page in the browser was eventually derived 
from the sketch, in that a different sketch would have resulted in a different 
web page"

<PROV-DM issue>
I have never been particularly comfortable with this attempt to capture the 
distinction between something that was merely involved and something that 
actively informed the resulting entity.  Philosophically, I think it's a very 
tricky distinction to draw.  Also, it draws us into discussion of what might 
have been, which is something I understand that provenance is not intended to 
capture.

In the primer example given about "DRAFT FOR REVIEW", maybe its presence does 
have an effect on the eventual document; if it were not present, the document 
might have been published without further revision.  Who knows?  I think there 
may be cases where the form of contribution is clearer and testable (e.g. 
becamePartOf),  but to simply distinguish between contributory and 
non-contributory derivation is, I think, rather hard to do.

My suggestion would be to drop the distinction, but to allow applications to 
specialize the property in ways that make sense for the application.
</PROV-DM issue>

Back to the primer:  I find that the distinction between eventuallyDeriuvedFrom 
and DerivedFrom is unclear.  I see two possible readings:
(a) derivedFrom indicates the activity by which derivation occurred, but 
eventuallyDerivedFrom does not
(b) derivedFrom is an account-dependent direct derivation by some activity 
(possibly unspecified) - (hence non-transitive), and eventuallyDerivedFrom is 
account-independent, transitive, possibly-indirect derivation.

<PROV-DM issue>
Is it possible to state that there is a direct derivation relation between two 
entities by some unspecified (existentially quantified) process execution?
</PROV-DM issue>

Hmmm... I'm finding the three cases in the primer don't seem to align with the 
current PROV-DM 
(http://dvcs.w3.org/hg/prov/raw-file/tip/model/ProvenanceModel.html#Derivation-Relation)

...

#g
--


On 15/11/2011 14:06, Simon Miles wrote:
> Hello all,
>
> The first draft of the primer document is ready for the WG to read and
> start raising issues against. It would be particularly helpful to know
> if the general approach/structure is one that makes sense to others.
>
> http://dvcs.w3.org/hg/prov/raw-file/default/primer/Primer.html
>
> It covers a subset of PROV-DM/-O that we thought was stable enough to
> explain and illustrate, and is definitely work in progress. It has
> PROV-O examples only, but we have asked Paolo to start considering ASN
> translations now this draft is out.
>
> Thanks in particular to Stephan and Stian for substantial efforts on
> the content of this draft (in addition to those of Yolanda and myself
> as editors).
>
> Thanks,
> Simon
>
Received on Thursday, 17 November 2011 10:42:19 UTC

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