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Re: Fwd: Going for simplicity (was: actions related to collections)

From: Graham Klyne <graham.klyne@zoo.ox.ac.uk>
Date: Tue, 01 May 2012 04:30:11 +0100
Message-ID: <4F9F58C3.8010104@zoo.ox.ac.uk>
To: W3C provenance WG <public-prov-wg@w3.org>
On 30/04/2012 11:28, Paul Groth wrote:
> Hi All,
> In Graham's comments, he put a rough number on the number of concepts
> namely 40. We are under that at 32 concepts this includes collections.

I was going to stand back a while from this discussion, but I think I must 
correct this (which may have been my own error) - the figure of 40 is total 
number of terms, including properties, not just concepts.

Actually, I think the ideal, for *really* large scale adoption, is under 20 
terms - concepts *and* properties.

(But of course the numbers are a bit arbitrary - my main point is that I think 
we are quite a way over the level of complexity that is likely to achieve really 
large-scale deployment.)

> Now in the ontology we have a bit more but this is because of the
> involvement pattern, which I think actually doesn't increase
> complexity as the pattern is systematic.

But I fear that's what developers will see.


> As it stands, I think the model that the group has put together
> strikes the right balance. We have a set of clear very small set of
> starting points and then have some additional things that are pretty
> core to provenance.
> I think there's an argument to be made to put collections/dictionary
> in a separate document for readability purposes but I think they
> should be part of the recommendation. There's been a lot of hard work
> there and the agreement seems to be that they are useful.
> cheers
> Paul
> On Mon, Apr 30, 2012 at 10:32 AM, Luc Moreau<L.Moreau@ecs.soton.ac.uk>  wrote:
>> Hi Stian,
>> Answer interleaved.
>> From: Stian Soiland-Reyes<soiland-reyes@cs.manchester.ac.uk>
>> Date: 29 April 2012 20:44:16 GMT+01:00
>> To: Graham Klyne<graham.klyne@zoo.ox.ac.uk>
>> Cc: Satya Sahoo<satya.sahoo@case.edu>,<public-prov-wg@w3.org>, Luc Moreau
>> <L.Moreau@ecs.soton.ac.uk>, Paolo Missier<Paolo.Missier@ncl.ac.uk>
>> Subject: Going for simplicity (was: actions related to collections)
>> 5, Insightful.
>> I agree on the general principle of simplicity. I had similar feelings when
>> wasQuoteOf and friends moved in, but have now grown to like the few
>> essential "real world" relations rather than having only a (easily verbose
>> and not very rich) entity-activity-agent model.
>> As you point out, a richer standard will also enable richer integration for
>> fewer clients.
>> One way towards having many adapters, some rich, is a simple core model, and
>> additional buy-in modules. The core gets everyone hooked, the modules gives
>> richness by giving a standard extension, "hey, you are thinking about
>> collections in your prov, how about checking out this bit over here".
>> But we need to make the essential modules. OPM suggested adapters to make
>> profiles and extensions, but I don't know of many such extensions in real
>> life. For instance DataOne is still working on agreeing how to do workflow
>> provenance using OPM.
>> Modules would also work as a kind of damage control. Let's say our view of
>> attribution turned out to be very wrong for digital publishing, however, our
>> view of derivation was a perfect fit. Adapters could choose to use PROV
>> derivations and make their own, richer attribution model. With one massive
>> model, we might easily put people off if one of our aspects are
>> wrong/naive/difficult compared to a domain's view.
>> I believe our current components in DM can form such a modularization.
>> However I have not read any recommendation about how these can be used in
>> such a pick-and-choose adaption, I thought they were merely rhetorical
>> groupings to ease understanding. Luc?
>> Yes, I saw components as a conceptual structuring of the data model, and not
>> as a way of optionally selecting which bit of the model we want to use.
>> There has been (so far!) no indication from the WG that we wanted to make
>> some part of the model optional.  This can be considered of course.
>> But to be effective, components need to be complementary. At the moment
>> derivations and responsibility are still entangled.
>> I don't think it's desirable.
>> Is your suggestion that we for instance have /ns/prov# (core),
>> /ns/prov-attribution# etc, or simply drop everything that is not "opmv
>> like"? (My question: why not then use opmv?)
>> I don't think we are keen to introduce multiple namespaces.
>> Luc
>> --
>> Stian Soiland-Reyes, myGrid team
>> School of Computer Science
>> The University of Manchester
>> On Apr 26, 2012 6:24 PM, "Graham Klyne"<graham.klyne@zoo.ox.ac.uk>  wrote:
>>> On 26/04/2012 13:39, Paolo Missier wrote:
>>>> Graham
>>>> you have made your point on this over and over again.
>>> Yes, I've said it before, but I think not (in this context) so much to
>>> count as "over and over again".  (Previously, I've objected to using
>>> collections to model provenance accounts, which was a different matter.)
>>>> ... I think we get it, but I
>>>> still don't see a strong argument. That is because the criteria used to
>>>> define
>>>> the scope here have been blurry and that has not improved with time.
>>>> The comments that followed my own personal opinion on this (attached)
>>>> seem to
>>>> indicate that capturing the evolution of sets may be a good idea, given
>>>> their
>>>> pervasiveness. If this belongs to a specific domain, which domain is it?
>>> Fair enough.  I'll see if I can substantiate my position...
>>> First, to be clear, I'm not saying that "capturing the evolution of sets"
>>> is not a good idea.  What I question is the extent to which is *should* be
>>> *entirely* down to the PROV spec to achieve this.
>>> We're defining a standard, and I think it's in the nature of standards for
>>> use on the global Internet/Web that the criteria for defining scope are
>>> blurry, because we can't expect to anticipate all of the ways in which they
>>> will be used.
>>> For me, the acid test will be the extent of adoption.  In my experience,
>>> it is the *simple* standards (of all kinds) that get more widely adopted.
>>>   TCP/IP vs OSI.  SMTP vs X.400.  HTTP vs any number of content management
>>> systems.
>>> I see the same for ontologies/vocabularies.  The widely used success
>>> stories are ones like DC, FOAF, SIOC, SKOS, etc., which all have the
>>> characteristic of focusing on a small set of core concepts.  Of course there
>>> are more specialized large ontologies/vocabularies that have strong
>>> following (e.g. a number of bioinformatics standards), but within much more
>>> confined communities.  (TimBL has a slide about costs of ontology vs size of
>>> community http://www.w3.org/2006/Talks/0314-ox-tbl/#(22) - it emphasizes the
>>> benefits of widespread adoption, but doesn't address costs associated with
>>> the *size* of the ontology.)
>>> In my view, provenance is something that /should/ be there with the likes
>>> of DC and FOAF in terms of adoption.  Which for me prioritizes keeping it as
>>> small as possible to maximize adoption.
>>> To repeat: I'm not saying that provenance of collections is not useful.
>>>   I'm sure it is very useful in many situations.  For me the test is not so
>>> much what is useful as what *needs* to be in the base provenance spec by
>>> virtue of it cannot reasonably be retro-fitted via available extension
>>> points.  What I have not seen is an explanation that the provenance of
>>> collections cannot be handled through specialization of the core provenance
>>> concepts we already have.  This might even be a separate *standard*.
>>> For me, all this is an an application of the principles of minimum power,
>>> independent invention and modularity
>>> (http://www.w3.org/DesignIssues/Principles.html).
>>> In many ways (and, to be clear, this is not a proposal, just an
>>> illustration) I'd rather like to see something like OPMV go forward as a
>>> base spec for provenance, because it's really clear from that what are the
>>> key ideas, and has they tie together.
>>> Many of the things the group spends time discussing (including, but
>>> limited to, collections) can be layered on this basic model.  The tension
>>> here is that by specifying more in the base model, one achieves a greater
>>> level of interoperability between systems *that fully implement the defined
>>> model*, and at the same time decrease the number of systems that attempt to
>>> implement the model.  This raises the question: is it more beneficial to
>>> have a relative few systems implement a very rich model of provenance
>>> interoperability, or to have very many systems implement a relatively weak
>>> model?  And of course, it's not black-or-white ... there are reasonable
>>> points between.   I think my view is clearly to "turn the dial" to the
>>> simpler end of the spectrum but, of course, YMMV.
>>>> But I am sorry that you are having to hold your nose. Believe me, the
>>>> provenance
>>>> of a set doesn't smell that bad.
>>> That was a figure of speech, and was probably an overly strong statement.
>>> As I say above, I'm sure provenance of collections of various kinds is
>>> useful and important - what I'm really trying to push on is how much needs
>>> to be in the base provenance specs that developers will have to master.
>>> I think I later in the discussion I saw a mention of abstract collections
>>> that could be specialized in different ways.  That, for me, could represent
>>> a reasonable compromise, though my preference would be to deal with
>>> collections separately.
>>> Maybe what I'm doing here is making a case for modularization of the
>>> provenance spec (ala PML?), rather lumping it all into one, er, collection.
>>> ...
>>> Returning to your comment about blurry criteria, here are some that are
>>> not blurry (though they are also unsubstantiated, but there are some clues
>>> at
>>> http://richard.cyganiak.de/blog/2011/02/top-100-most-popular-rdf-namespace-prefixes/):
>>> * I think that if we can produce of base provenance ontology of<=8
>>> classes<=12 properties, we stand a chance of deployment at the scale of
>>> FOAF (the numbers are approximately the size of FOAF core -
>>> http://xmlns.com/foaf/spec/)
>>> * I think a base ontology with twice the number of classes could achieve
>>> less than 10% of the adoption of FOAF (e.g. compare interest in vCard vs
>>> FOAF or DC at
>>> http://richard.cyganiak.de/blog/2011/02/top-100-most-popular-rdf-namespace-prefixes/
>>> * I think a base ontology with substantially more terms will receive
>>> substantially less adoption.
>>> The numbers here are, to be sure, very unscientific.  But it's interesting
>>> that, not counting the "infrastructure" ontologies (rdf, rdfs, owl, ex), all
>>> the "high interest" ontologies that I probes were also relatively small (up
>>> to 40 terms overall at a rough guess)
>>> On this basis, my criterion becomes very un-blurry: fewer terms is better
>>> by far.
>>> Of course, there's a balance to be struck, but it brings home to me that
>>> each term that is added to the overall provenance ontology has to bring
>>> substantial benefit if the adoption (impact) of our work is not to be
>>> reduced.
>>> ...
>>> Finally, the reason I think that PROV *could* be as popular as FOAF is
>>> because it is positioned to underpin a key missing feature of the web -
>>> providing a machine actionable basis for dealing with conflicting
>>> information (trust, information quality assessment).  It could be, in a real
>>> sense, the FOAF of data ("who are you?", "who do you know?", "where do you
>>> come from?", etc.).
>>> As yet, we don't *know* what aspects of provenance will be important in
>>> this respect, though there is some research (including your own, Paolo) that
>>> suggests some directions.  So, in pursuit of this goal, the thing about PROV
>>> that matters almost more than anything else is scale of adoption.  So, on
>>> this view, *anything* that stands in the way of adoption without providing
>>> needed functionality that cannot be achived in any other way is arguably an
>>> impediment to the eventual success of PROV.
>>> #g
>>> --
>>>> On 4/26/12 12:04 PM, Graham Klyne wrote:
>>>>> I find myself somewhat concerned by what appears to be scope creep
>>>>> associated
>>>>> with collections. It seems to me that in the area, the provenance model
>>>>> is
>>>>> straying in the the domain of application design. If collections were
>>>>> just
>>>>> sets, I could probably hold my nose and say nothing, but this talk of
>>>>> having
>>>>> provenance define various forms of collection indexing seems to me to be
>>>>> out of
>>>>> scope.
>>>>> So I think this is somewhat in agreement with what Satya says here,
>>>>> though I
>>>>> remain unconvinced that the notions of collections and
>>>>> derivation-by-insertion,
>>>>> etc., actually *need* to be in the main provenance ontology - why not
>>>>> let
>>>>> individual applications define their own provenance extension terms?
>>>>> #g
>>>>> --
>>>>> On 18/04/2012 17:35, Satya Sahoo wrote:
>>>>>> Hi all,
>>>>>> The issue I had raised last week is that collection is an important
>>>>>> provenance construct, but the assumption of only key-value pair based
>>>>>> collection is too narrow and the relations derivedByInsertionFrom,
>>>>>> Derivation-by-Removal are over specifications that are not required.
>>>>>> I have collected the following examples for collection, which only
>>>>>> require
>>>>>> the definition of the collection in DM5 (collection of entities) and
>>>>>> they
>>>>>> don't have (a) a key-value structure, and (b) derivedByInsertionFrom,
>>>>>> derivedByRemovalFrom relations are not needed:
>>>>>> 1. Cell line is a collection of cells used in many biomedical
>>>>>> experiments.
>>>>>> The provenance of the cell line (as a collection) include, who
>>>>>> submitted
>>>>>> the cell line, what method was used to authenticate the cell line, when
>>>>>> was
>>>>>> the given cell line contaminated? The provenance of the cells in a cell
>>>>>> line include, what is the source of the cells (e.g. organism)?
>>>>>> 2. A patient cohort is a collection of patients satisfying some
>>>>>> constraints
>>>>>> for a research study. The provenance of the cohort include, what
>>>>>> eligibility criteria were used to identify the cohort, when was the
>>>>>> cohort
>>>>>> identified? The provenance of the patients in a cohort may include
>>>>>> their
>>>>>> health provider etc.
>>>>>> Hope this helps our discussion.
>>>>>> Thanks.
>>>>>> Best,
>>>>>> Satya
>>>>>> On Thu, Apr 12, 2012 at 5:06 PM, Luc
>>>>>> Moreau<L.Moreau@ecs.soton.ac.uk>wrote:
>>>>>>> Hi Jun and Satya,
>>>>>>> Following today's call, ACTION-76 [1] and ACTION-77 [2] were raised
>>>>>>> against you, as we agreed.
>>>>>>> Cheers,
>>>>>>> Luc
>>>>>>> [1]
>>>>>>> https://www.w3.org/2011/prov/**track/actions/76<https://www.w3.org/2011/prov/track/actions/76>
>>>>>>> [2]
>>>>>>> https://www.w3.org/2011/prov/**track/actions/77<https://www.w3.org/2011/prov/track/actions/77>
>> --
>> 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 Tuesday, 1 May 2012 03:31:05 GMT

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