- From: Graham Klyne <GK@ninebynine.org>
- Date: Tue, 31 May 2011 14:25:22 +0100
- To: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
- CC: public-prov-wg@w3.org
Luc Moreau wrote: > Hi Jun, Daniel, Stephan, > > Thanks for your proposed definitions: > > I don't understand how the proposed definitions of Derivation > would work in the presence of mutable resources. > > So, to illustrate this, I consider the following variant of our example > > > - blogger (bob) generates new chart (c2) based on the data (lcp2) using > some software (tools2) with statistical assumptions (stats2) > - blogger (bob) publishes the chart (c2) under an open license (li3). > - user (u1) visualises chart (c2) > - later, blogger (bob) updates published chart (c2) rerunning (tools2) > using other statistical assumptions (stats3) > - user (u2) visualises chart the latest (c2) > > > I would argue that we have: > - a derivation from a downloaded copy of c2 to stats2 (as seen by u1) > - another derivation from another downloaded copy of c2 to stats3 (as > seen by u2) > > Hence, it does not seem appropriate to relate resource c2 directly to > stats2 or stats3. > Instead, I think we should relate the resource state representations of > c2 (the downloaded copies) > to stats2 and stats3, respectively. > > What do you think? I see (at least) two resources associated with (c2): one generated using (stats2), and other using (stats3). We might call these (c2s2) and (c2s3). If we then regard the resource (c2) to be the dynamically evolving chart of (lcp2) created by (bob) using (tools2), the interesting question becomes if and how (c2) participates in an account of provenance. A view that I'd suggest is that if (pc2) is a resource describing the provenance of (c2), then both are dynamic resources. For many purposes, this may be fine; e.g. a stock price based on market information as of 15 minutes ago seems to me to be a perfectly useful statement of provenance, even if the information itself doesn't have enduring value. It may be that some formal analyses depend on the resource and/or associated provenance being non-dynamic. That's fine, but I suggest it's a constraint on the utility of the formal analysis and should be introduced as such, rather than an inherent constraint on the nature of provenance. I accept this view is an assumption: a position of choice, not necessity. But I think we can have a very simple initial account of provenance if we don't limit the things about which we can reasonably assert provenance. The disadvantage of such an approach is that, of itself, it's inferentially less powerful. But here we touch on a problem that dogges the whole semabtic web initiative for some time in its early years: the presumption of a need for inferential power. But when we look at practical applications of SemWeb ideas, the role of inference is, I believe, quite limited. #g -- > On 05/31/2011 11:56 AM, Jun Zhao wrote: >> Hi Daniel, >> >> On 27/05/2011 12:04, Daniel Garijo wrote: >>> Hi Luc, all >>> In the example c2 is also a derivation of d2, and from my point of view, >>> c2 could also be seen as a derivation from c1, since it is the chart >>> taken as reference >>> and corected in c2... >>> >>> As for your second question, I think that if we want to be able to cover >>> provenance from resources, resources representations and resources state >>> representation, a derivation must be able to refer to all of them. >> >> That's why in the current wiki page defining derivation I used some >> very vague terminologies. >> >> I think derivation should cover all the cases you listed above. And we >> should start to clearly define the three above concepts in order to >> define the rest provenance terms as accurately as we can for the moment. >> >> cheers, >> >> Jun >> >>> >>> What do you think? >>> Best, >>> Daniel >>> >>> 2011/5/27 Luc >>> Moreau<L.Moreau@ecs.soton.ac.uk<mailto:L.Moreau@ecs.soton.ac.uk>> >>> >>> Dear all, >>> >>> Over the last week, we debated the notion of resource (PROV-ISSUE-1), >>> one of the concepts identified in the charter as core to a provenance >>> data model. It would be good to discuss the notion of derivation. >>> >>> Do we agree with the illustration of derivation [1]: >>> in the example, chart c1 is a derivation of data set d1. >>> Are there other interesting illustrations? >>> >>> Is derivation relating resources/resource representations/resource >>> representation states? >>> >>> Cheers, >>> Luc >>> >>> [1] http://www.w3.org/2011/prov/wiki/CharterConceptsIllustration >>> >>> >>> >>> >>> >>> On 05/20/2011 08:07 AM, Provenance Working Group Issue Tracker wrote: >>> PROV-ISSUE-7 (define-derivation): Definition for Concept 'Derivation' >>> [Provenance Terminology] >>> >>> http://www.w3.org/2011/prov/track/issues/7 >>> >>> Raised by: Luc Moreau >>> On product: Provenance Terminology >>> >>> The Provenance WG charter identifies the concept 'Derivation' as a >>> core concept of the provenance interchange language to be >>> standardized (see http://www.w3.org/2011/01/prov-wg-charter). >>> >>> What term do we adopt for the concept 'Derivation'? >>> How do we define the concept 'Derivation'? >>> Where does concept 'Derivation' appear in ProvenanceExample? >>> Which provenance query requires the concept 'Derivation'? >>> >>> Wiki page: http://www.w3.org/2011/prov/wiki/ConceptDerivation >>> >>> >>> >>> >>> >>> >>> -- >>> 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<mailto:l.moreau@ecs.soton.ac.uk> >>> United Kingdom >>> http://www.ecs.soton.ac.uk/~lavm<http://www.ecs.soton.ac.uk/%7Elavm> >>> >>> >>> >>> >> >> >
Received on Tuesday, 31 May 2011 14:16:42 UTC