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Re: release of prov-dm, prov-dm-constraints, and prov-n for review

From: Khalid Belhajjame <Khalid.Belhajjame@cs.man.ac.uk>
Date: Mon, 09 Apr 2012 13:48:24 +0100
Message-ID: <4F82DA98.4000508@cs.man.ac.uk>
To: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
CC: Provenance Working Group WG <public-prov-wg@w3.org>

Hi,

Here are some comments on the 5th working draft of the prov-dm.
Generally, it reads well, the focus in the comments below are on the 
changed made since the last working draft.

Thanks, khalid

-------------
- In the beginning of the working draft "How to read the PROV Family", 
it is said that "Developers seeking to retrieve or publish provenance 
should focus *on* PROv-AQ". Given the discussion that we had few weeks 
ago on using a SPARQL end point to query provenance that is encoded 
using provo. I would add PROVO as well to that sentence.

- Fourth public working draft -> Fifth working draft

- 1.1 Structure of the document. "... which are allows users" -> "which 
allow users"

- 2.2 Generation, Usage, Derivation
In the definition of Usage it is said that "Before usage, the activity 
had not begun to consume or use this entity and could not have been 
affected by the entity". I note that this sentence assumes that an 
entity can be used only once by an activity. In practice, the same 
activity can use the same entity, for example with different roles.

- The usage example states situations in which the usage implies that 
the activity consumes the entity, and others in which the entity remains 
intact. Will is be useful to distinguich these two kinds of usage 
explicitly, by specializing the usage relation? In particular, I note 
that the notion of consumption entails interesting properties such as 
the invalidation of an entity and the fact that an entity can be 
consumed by at most one activity.

- 3.1 Illustration of PROV-DM by an example.
I find this section hard to read, and this is not the first time I read 
it. I think its readability can be improved if the following comments 
are considered. - In the text, the first and second working draft are 
referred using identifiers that are not intuitive, tr:WD-prov-dm-201.... 
I am not suggesting not to use them, but to specify whether they 
represent the first or the second working draft, whenever they are used 
in the text. - The figure given at the end of Sectio 3.1 can be more 
helpful in guiding the reader if it placed earlier in that section. - 
Talkiing about the figure the fact there are two arrows that link an 
arrow to a class, I understand their meaning, by I am not sure the 
reader will. - Section 3.2 giving information about the provenance form 
the author point of view seems to be simpler, and I think it would be 
better to start by the provenance from the author point of view before 
presenting the provenance from the process point of view.

- 4: PROV-DM Types and Relations
I am not sure the notion of component helps in the readability of the 
document. Refering to component1, component 2, etc. in the text is not 
helpful. I guess the only justification of using the term component is 
Figure PROV-DM component, which shows dependencies between those 
component. That said, I don't think that figure is helpful. It simply 
used to specify that one concept or a relation in a component depends on 
one concept or relation in another component. I note also that the term 
component is used in the text to refers to the definition elements in 
PROV-N. I would therefore suggest not ti use the notion of component, 
and rather use directly heading such as "Entity, Activity and their 
Relations", "Agent and their Responsibility", etc.

- One of the consequence of trying to structure the model into 
component, is the fact that the reader will have to read the details of 
communication and start by activity, before reaching the definition of 
agent, responsibility and derivation, which are far more important for 
the ordinary reader. That said, I think the starting point which are in 
the beginning of the document already introduced the main concepts and 
relations.

- 4.1.8 Start by Activity
In the example given it is not explained why a2 was started by a1. There 
is an assumption that the reader will understand that a sub-workflow 
will be started by the parent workflow. I think this should explicitly 
stated.

- 4.4.1 Specialization
In the first paragraph: "common entity" -> "common thing"

-4.5 Component 5: Collections
I think that there is a need for defining collection here.
Although it is stated that a collection is an entity. I feel there is a 
need for specifying what the members of a collection are as part of the 
collection specification, even when the specification of those members 
is optional.
The membership relation fulfills the above requirements only partly, it 
is meant to specify a subset of the members that belong to a collection, 
not necessarily all of them.
Therefore, I would suggest using a dedicated chracterizing attribute 
"members" for entities that happen to be collections.

For example, we can define a collection c1 as
entity (c1, [prov:type="Collection", prov:members = {<k1,v1>,...,<kn,vn>}]


On 02/04/2012 22:25, Luc Moreau wrote:
> Dear all
>
> As agreed, we are releasing three documents for review today.
>
> Objectives of the review and reviewers were listed in last week's
> teleconference agenda:
> http://www.w3.org/2011/prov/wiki/Meetings:Telecon2012.03.29#PROV-DM
>
> The documents are the following:
>
> *PROV-DM:*
> http://dvcs.w3.org/hg/prov/raw-file/default/model/releases/ED-prov-dm-20120402/prov-dm.html
> issues to be raised against http://www.w3.org/2011/prov/track/issues/331
>
> *PROV-DM-CONSTRAINTS:*
> http://dvcs.w3.org/hg/prov/raw-file/default/model/releases/ED-prov-dm-20120402/prov-dm-constraints.html
> issues to be raised against http://www.w3.org/2011/prov/track/issues/333
>
> *PROV-N:*
> http://dvcs.w3.org/hg/prov/raw-file/default/model/releases/ED-prov-dm-20120402/prov-n.html
> issues to be raised against http://www.w3.org/2011/prov/track/issues/332
>
>
> Everybody is of course welcome to provide comments on these documents.
>
> Best regards,
> Luc
Received on Monday, 9 April 2012 12:49:11 GMT

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