W3C home > Mailing lists > Public > public-prov-wg@w3.org > March 2012

Re: PROV-DM (DM4) - review up to section 4.2.3.3

From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
Date: Fri, 23 Mar 2012 13:09:06 +0000
Message-ID: <EMEW3|ba4ae9ab2098b51b24122d3df1315379o2MD9B08L.Moreau|ecs.soton.ac.uk|4F6C75F2.9070803@ecs.soton.ac.uk>
To: public-prov-wg@w3.org, Graham Klyne <GK@ninebynine.org>
Hi Graham,

Thanks for your feedback.  We have incorporated some of your suggestions 
in the
current editor's draft [1]

Find below our response to your individual points.

If you think that some of these points are going to be blockers for the 
release of WD5 or LC, it would
be useful if you could raise them now, so that we can discuss them by email,
and find a solution before you review again the document in 10 days 
time, or so.

In particular, after careful consideration, Paolo and I think that:
- Overview diagram should remain in section 2.5
- Example of section 3 should remain there
- AlternateOf/SpecializationOf are part of prov-dm and should be 
presented in this document
- Notions of responsibility, agents and plan were debated at length in 
ISSUE-203 which is now
   closed, and we are not proposing to reopen it, unless new evidence is 
offered.

Regards,
Luc

[1] http://dvcs.w3.org/hg/prov/raw-file/default/model/prov-dm.html

 > Summary: I think the content is generally a big improvement, but there
 > are some possible further removals, and I think there remain a number
 > of document quality issues to be addressed before getting to last
 > call.  Hopefully, these can be considered in DM5
 >
 > When the content stabilizes, I may offer some alternate drafting
 > suggestions, but I think it's in too much flux right now for that to
 > be worthwhile.
 >
 > ...
 >
 > Re: http://dvcs.w3.org/hg/prov/raw-file/f52c0bb53dd4/model/prov-dm.html
 > (Retrieved 2012-30-08)
 >
 > I'd wish to see all references to "things in the world" expunged: it's
 > an ugly expression that begs more questions than it answers, and IMO
 > runs the risk of confusing readers.


OK, no longer talk about "thing in the world" but "thing".


 >
 > Section 1 intro: rewording in 1st 3 paras.
 >
 > Suggest that the provenance notation be a part 1 appendix, not a
 > separate part/document.  Drop references to ASN - it's *not* an
 > *abstract* syntax notion; indeed, I think that very expression is an
 > oxymoron.

We now call it PROV-N.

Having gone through the process of writing productions fully, there
are some grammatical syntactic details that have no place in the PROV-DM 
document.
Also, PROV-N  provides examples of instances to explain the grammar.
This has no place in the PROV-DM document either.

Furthermore, past experience has shown that readers confuse prov-dm and 
prov-n.

So, the editor's recommendation is to keep the documents separate.
 >
 > Part 2 is *not* an upgrade path. Please don't say this.  (It's a
 > refinement of use that allows provenance information from different
 > sources to be combined in meaningful ways.)


Replaced 'upgrade path' by 'refinement'


 >
 > More text refinement in section 1.
 >
 >
 > Section 2.1
 >
 > Saying "Activity is anything ..." is confusing.  It suggests a
 > continuant rather than an occurrent.

Rephrased as follows:

An activity is something that occurs and acts upon or with entities.


 >
 > Sub-editing would improve this.
 >
 >
 > Section 2.2
 >
 > I think it would be clearer if generation and usage were introduced as
 > events associated with activities.  (Discussion of them being
 > instantaneous can come in Part 2)

It was agreed at F2F2 that we shouldn't introduce event in part 1.
We followed this guidance.  The term event is only defined in part 2.


 >
 > Introducing generation as "completed production" reads really
 > strangely to me, and sounds as if it could be a produced artifact.  I
 > think a form like "completion of production" is clearer.  Similarly
 > for usage, something like "starting to consume".
 >

Updated definitions as follows:

Generation is the completion of production of a new entity by an activity.

Usage is the beginning of consumption of a new entity by an activity.


 > Sub-editing would improve this.
 >
 >
 > Section 2.3:
 >
 > "AccountEntity" - why not just "Account".  Also, I understood this was
 > to *be* a bundle, not a container for a bundle.

To be addressed, once other editing work for WD5 is completed.

The two notions (container vs bundle) are useful, for different purposes.
To be investigated.


 >
 > The example given has no clear relationship to the description.  I
 > understood the key use-case here was to express provenance of
 > procenance, and that is why we have accounts.  I think that should be
 > stated clearly; e.g.

This is made clearer, following definition and in example.

 >
 > "An account is a bundle of provenance statements treated as an entity
 > which may itself have some associated provenance."
 >

Subtle difference again: "... treated as an entity ..." vs " ... is an 
entity ..."

We can definitely add "... which may itself have some associated 
provenance "


 >
 > Agents.  I think the notion of responsibility here is so loose as to
 > be of no practical value.  When we say a text editor is "responsible
 > for" crashing a computer, that's a kind of anthropomorphism, not a
 > literal claim of responsibility.  What we really mean is that the text
 > editor caused the crash. The notion of responsibility is generally
 > associated with duty, authority and/or accountability
 > (cf. http://oxforddictionaries.com/definition/responsibility?view=uk).
 > This is why persons and organizations are distinct from software
 > agents.  I suggest that the text here should "stick to the knitting":
 > just state that these are commonly encountered kinds of agent, and
 > leave it at that.


The example about software agent was simplified. Indeed no need to 
mention responsibility here.
This is left to section 2.4.

 >
 >
 > Section 2.4
 >
 > This continues the muddle about "responsibility", until the definition
 > of agent responsibility realtion which seems about right to me (note
 > the phrase "accountable for" here).
 >
 > The use of responsibility in the description of association seems
 > completely wrong to me.

What would you suggest?

 >
 > The discussion of activity association is surreal.  A plan is defined
 > previously as an "Entity", but association relates an *agent* to an
 > activity.

It's a ternary relation.
This was discussed at length in ISSUE-203, which is now closed.

I am not proposing to reopen it, unless new information is brought forward.

 >
 > I think this section needs re-drafting.
 >
 >
 > Section 2.5
 >
 > I think the intent and content of the diagram is generally good, but
 > that its visual presentation could usefully be improved.  I think it
 > should appear as part of the introduction to section 2, not at the
 > end.
 >

We are now generating a PNG, so hopefully its better.

After careful consideration, we felt it was better to leave it in 
section 2.5, in part,
because we need to map the concepts (expressed in natural language) to 
prov-dm types/relations.



 >
 > Generally in section 2, I think the examples are mostly well-chosen,
 > but their presentation breaks up the flow of the overview; I woukd
 > prefer that the examples were more succinct, maybe fewer, and
 > introduced inline in the descriptive overview text.  Ideally the whole
 > overview would fit on just one or two pages (i.e. about half its
 > current length on a printed page).  The key purpose here, IMO, is to
 > give a quick overview of how the various concepts are used together.
 >
 >

Usual trade-off. Now that concepts seem clearer, than we don't need 
examples.

I think that examples are clearly delimited and can be skipped if the 
reader wants.



 > Section 3:
 >
 > I don't find this example at all helpful.  It requires too much effort
 > to understand, and I find the process view vs author view is
 > confusing.  What is this section actually trying to tell the reader?
 > I can't tell.

Publishing of documents and their provenance on the Web.
It seems that it is a primary use case for this specification.

 >
 > I think a comprehensive example like this would be better sited as an
 > appendix, rather than an interruption to the main flow of the
 > document.

We received positive feedback about the example, and in particular that
it deals with attribution of provenance.

 >
 >
 > Section 4.1:
 >
 > I find the sub-heading "Element" is confusing/unhelpful.
 >

Gone with the new component structure.


 >
 > Section 4.1.1 - verbatim repetition of text defining "Entity" already
 > present in section - this is unhelpful.

Section 4 contains the systematic presentation of all types and relations.
Given that many had not been (and should not be) introduced in the
"starting point section", it is better to have *all* terms defined in 
section 4.


 >
 > The description of the provenance notation expressions should use the
 > same terms as are used in the template presented; i.e.. *not* "[
 > attr=val1, ... ]" and "attributes".
 >

The template shows instances of arguments, where as the descriptions
provide names for attributes.

 > Don't need to say anything about disjointness of entities and
 > activities in Part 1.
 >

This seems in conflict with the next comment.  Or is it just about the
English (avoiding disjoint term)?

 >
 > Secftion 4.1.2
 >
 > Similar comments to section 4.1.1
 >
 > (But I think the simple statement "An activity is not an entity ..."
 > is good.)
 >
 >
 > Section 4.1.3
 >
 > Similar comments to section 4.1.1
 >
 > Don't need to say why sub-categories of agent are introduced.

why not?  In particular, this was introduced in response to feedback
from the working group.

 >
 > I would probably avoid making the mutual exclusivity claim (legally,
 > it may be or become a debatable point).
 >

OK

 >
 > Section 4.1.4
 >
 > I don't see that notes are an essential part of the provenance
 > structure.  I'd prefer to drop them, as I don't see them adding any
 > expressive capability.

This is ISSUE-260, potentially related to account. We will tackle
this once we have some bandwidth.

To me, it's crucial to be able to annotate provenance, and to do so in
an inter-operable way, whatever the serialization.

The questioni is whether the mechanism presented here is the right
one, or, as Tim suggests, Accounts take care of that.


 >
 >
 > Section 4.2
 >
 > The table of different relation domain and range combinations is fair
 > enough, but I'm not convinced the additional level of document
 > structure reflecting this is useful.

Table was kept as a form of index.
Structure changed to components.

 >
 > Ideally, I think the relations would all appear at the same document
 > level as the concepts, so they have a similar "visual signature" when
 > scanning the document.

All done.

 >
 > Most or all subsections have repetition of text from section 2 similar
 > to that noted for section 4.1.1

Some are repeat, some are new, as indicated above.

 >
 > Also, most sections seem to suffer from a similar mismatch between the
 > provenance notation template given and the accompanying description of
 > the constituent elements.

The template shows instances of arguments, where as the descriptions
provide names for attributes.

 >
 > I think generation and usage should be described as events (not
 > necxessarily to introduce a formal notion of events, just make it
 > clear that they are events corresponding to some change in the
 > relationship between an entity and an activity)
 >

See comment above.

 >
 > Section 4.2.2.1
 >
 > "Responsibility" again.
 >
 > There are two things going on here that I feel are very muddled:
 >
 > (a) this rather odd notion of responsibility, and
 >
 > (b) associating a plan with an activity.
 >
 > At the very least, I think these aspects should be separated, not just
 > lumped into an single overloaded element.

This was discussed at length in ISSUE-203, which is now closed. see above.

 >
 > I'm not sure why some expression components are explicit and possibly
 > optional parameters, while athewrs are attributes.  What's the
 > intended difference here?

For rationale see:

http://dvcs.w3.org/hg/prov/raw-file/default/model/prov-n.html#positional-vs-named-attributes

 >
 >
 > Section 4.2.3.1
 >
 > Responsibility again.  In this case, I think there may be some
 > justification for talking about responsibility, but earlier treatment
 > of this idea makes it hard for me to know what is really being
 > expressed.  I think it is the notion that some actions of one agent
 > are authorized or controlled by another agent in the context of a
 > given activity, hence any accountability for the outcome may propagate
 > back to the controlling or authorizing agent.  But that's not entirely
 > clear to me from the text.
 >
 > Also, I can't tell if the structures here would accommodate different
 > agents having different responsibilities.  E.g. a manager authorizes
 > an engineer to purchase a component, but is then instructed by the
 > engineer in its deployment/installation...  when the component fails
 > to achieve some required outcome, who is accountable?  The manager for
 > not authorizing enough funds, or the engineer for not properly
 > explaining how to use the component?
 >
 >

PROV-DM allows you to express the relations.
If I understood correctly, we have:

wasGeneratedBy(component,purchase)
actedOnBehalfOf(engineer,manager,purchase, [role="line management"])
actedOnBehalfOf(manager,engineer,deployment, [role="technical guidance"])

PROV-DM does not say how to reason about responsibility.
What is the answer to your question?

This said, did you mean
  actedOnBehalfOf(manager,engineer,deployment, [role="technical guidance"])
or  did you mean:
  wasInformedBy(manager,engineer)


 > Section 4.2.3.2
 >
 > Skipped - I understand this is due to be replaced.  (Despite my
 > reservations expressed elsewhere, the replacement looks like a
 > significant improvement.)
 >
 >
 > Section 4.2.3.3
 >
 > Do we still need Alternate and Specialization in the provenance
 > notation?


Do you mean in PROV-DM?

Yes, I think these are relations of the data model. They need
to be introduced in this document.



 >
 > ...
 >
 > I'm running out of time, so I'll stop here.
 >


Thanks,
 >
 >
 >


On 03/08/2012 03:49 PM, Graham Klyne wrote:
> Summary:  I think the content is generally a big improvement, but 
> there are some possible further removals, and I think there remain a 
> number of document quality issues to be addressed before getting to 
> last call.  Hopefully, these can be considered in DM5
>
> When the content stabilizes, I may offer some alternate drafting 
> suggestions, but I think it's in too much flux right now for that to 
> be worthwhile.
>
> ...
>
> Re: http://dvcs.w3.org/hg/prov/raw-file/f52c0bb53dd4/model/prov-dm.html
> (Retrieved 2012-30-08)
>
> I'd wish to see all references to "things in the world" expunged: it's 
> an ugly expression that begs more questions than it answers, and IMO 
> runs the risk of confusing readers.
>
> Section 1 intro: rewording in 1st 3 paras.
>
> Suggest that the provenance notation be a part 1 appendix, not a 
> separate part/document.  Drop references to ASN - it's *not* an 
> *abstract* syntax notion; indeed, I think that very expression is an 
> oxymoron.
>
> Part 2 is *not* an upgrade path. Please don't say this.  (It's a 
> refinement of use that allows provenance information from different 
> sources to be combined in meaningful ways.)
>
> More text refinement in section 1.
>
>
> Section 2.1
>
> Saying "Activity is anything ..." is confusing.  It suggests a 
> continuant rather than an occurrent.
>
> Sub-editing would improve this.
>
>
> Section 2.2
>
> I think it would be clearer if generation and usage were introduced as 
> events associated with activities.  (Discussion of them being 
> instantaneous can come in Part 2)
>
> Introducing generation as "completed production" reads really 
> strangely to me, and sounds as if it could be a produced artifact.  I 
> think a form like "completion of production" is clearer.  Similarly 
> for usage, something like "starting to consume".
>
> Sub-editing would improve this.
>
>
> Section 2.3:
>
> "AccountEntity" - why not just "Account".  Also, I understood this was 
> to *be* a bundle, not a container for a bundle.
>
> The example given has no clear relationship to the description.  I 
> understood the key use-case here was to express provenance of 
> procenance, and that is why we have accounts.  I think that should be 
> stated clearly; e.g.
>
> "An account is a bundle of provenance statements treated as an entity 
> which may itself have some associated provenance."
>
>
> Agents.  I think the notion of responsibility here is so loose as to 
> be of no practical value.  When we say a text editor is "responsible 
> for" crashing a computer, that's a kind of anthropomorphism, not a 
> literal claim of responsibility.  What we really mean is that the text 
> editor caused the crash. The notion of responsibility is generally 
> associated with duty, authority and/or accountability (cf. 
> http://oxforddictionaries.com/definition/responsibility?view=uk).  
> This is why persons and organizations are distinct from software 
> agents.  I suggest that the text here should "stick to the knitting": 
> just state that these are commonly encountered kinds of agent, and 
> leave it at that.
>
>
> Section 2.4
>
> This continues the muddle about "responsibility", until the definition 
> of agent responsibility realtion which seems about right to me (note 
> the phrase "accountable for" here).
>
> The use of responsibility in the description of association seems 
> completely wrong to me.
>
> The discussion of activity association is surreal.  A plan is defined 
> previously as an "Entity", but association relates an *agent* to an 
> activity.
>
> I think this section needs re-drafting.
>
>
> Section 2.5
>
> I think the intent and content of the diagram is generally good, but 
> that its visual presentation could usefully be improved.  I think it 
> should appear as part of the introduction to section 2, not at the end.
>
>
> Generally in section 2, I think the examples are mostly well-chosen, 
> but their presentation breaks up the flow of the overview; I woukd 
> prefer that the examples were more succinct, maybe fewer, and 
> introduced inline in the descriptive overview text.  Ideally the whole 
> overview would fit on just one or two pages (i.e. about half its 
> current length on a printed page).  The key purpose here, IMO, is to 
> give a quick overview of how the various concepts are used together.
>
>
> Section 3:
>
> I don't find this example at all helpful.  It requires too much effort 
> to understand, and I find the process view vs author view is 
> confusing.  What is this section actually trying to tell the reader?  
> I can't tell.
>
> I think a comprehensive example like this would be better sited as an 
> appendix, rather than an interruption to the main flow of the document.
>
>
> Section 4.1:
>
> I find the sub-heading "Element" is confusing/unhelpful.
>
>
> Section 4.1.1 - verbatim repetition of text defining "Entity" already 
> present in section - this is unhelpful.
>
> The description of the provenance notation expressions should use the 
> same terms as are used in the template presented;  i.e.. *not* "[ 
> attr=val1, ... ]" and "attributes".
>
> Don't need to say anything about disjointness of entities and 
> activities in Part 1.
>
>
> Secftion 4.1.2
>
> Similar comments to section 4.1.1
>
> (But I think the simple statement "An activity is not an entity ..." 
> is good.)
>
>
> Section 4.1.3
>
> Similar comments to section 4.1.1
>
> Don't need to say why sub-categories of agent are introduced.
>
> I would probably avoid making the mutual exclusivity claim (legally, 
> it may be or become a debatable point).
>
>
> Section 4.1.4
>
> I don't see that notes are an essential part of the provenance 
> structure.  I'd prefer to drop them, as I don't see them adding any 
> expressive capability.
>
>
> Section 4.2
>
> The table of different relation domain and range combinations is fair 
> enough, but I'm not convinced the additional level of document 
> structure reflecting this is useful.
>
> Ideally, I think the relations would all appear at the same document 
> level as the concepts, so they have a similar "visual signature" when 
> scanning the document.
>
> Most or all subsections have repetition of text from section 2 similar 
> to that noted for section 4.1.1
>
> Also, most sections seem to suffer from a similar mismatch between the 
> provenance notation template given and the accompanying description of 
> the constituent elements.
>
> I think generation  and usage should be described as events (not 
> necxessarily to introduce a formal notion of events, just make it 
> clear that they are events corresponding to some change in the 
> relationship between an entity and an activity)
>
>
> Section 4.2.2.1
>
> "Responsibility" again.
>
> There are two things going on here that I feel are very muddled:
>
> (a) this rather odd notion of responsibility, and
>
> (b) associating a plan with an activity.
>
> At the very least, I think these aspects should be separated, not just 
> lumped into an single overloaded element.
>
> I'm not sure why some expression components are explicit and possibly 
> optional parameters, while athewrs are attributes.  What's the 
> intended difference here?
>
>
> Section 4.2.3.1
>
> Responsibility again.  In this case, I think there may be some 
> justification for talking about responsibility, but earlier treatment 
> of this idea makes it hard for me to know what is really being 
> expressed.  I think it is the notion that some actions of one agent 
> are authorized or controlled by another agent in the context of a 
> given activity, hence any accountability for the outcome may propagate 
> back to the controlling or authorizing agent.  But that's not entirely 
> clear to me from the text.
>
> Also, I can't tell if the structures here would accommodate different 
> agents having different responsibilities.  E.g. a manager authorizes 
> an engineer to purchase a component, but is then instructed by the 
> engineer in its deployment/installation...  when the component fails 
> to achieve some  required outcome, who is accountable?  The manager 
> for not authorizing enough funds, or the engineer for not properly 
> explaining how to use the component?
>
>
> Section 4.2.3.2
>
> Skipped - I understand this is due to be replaced.  (Despite my 
> reservations expressed elsewhere, the replacement looks like a 
> significant improvement.)
>
>
> Section 4.2.3.3
>
> Do we still need Alternate and Specialization in the provenance notation?
>
> ...
>
> I'm running out of time, so I'll stop here.
>
>
>

-- 
Professor Luc Moreau
Electronics and Computer Science   tel:   +44 23 8059 4487
University of Southampton          fax:   +44 23 8059 2865
Southampton SO17 1BJ               email: l.moreau@ecs.soton.ac.uk
United Kingdom                     http://www.ecs.soton.ac.uk/~lavm
Received on Friday, 23 March 2012 13:09:53 GMT

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