- From: Luc Moreau <L.Moreau@ecs.soton.ac.uk>
- Date: Tue, 13 Mar 2012 22:24:53 +0000
- To: public-prov-wg@w3.org
Hi Curt, Responses interleaved. On 13/03/12 20:02, Curt Tilmes wrote: > On 03/13/2012 07:59 AM, Luc Moreau wrote: >>> So if I, for example, download those proceedings prior to their >>> disappearance, then at some later time, perform some activity based on >>> those proceedings, while my activity "used" the proceedings >>> themselves, it doesn't (can't) use the entity chicago:wkshp2002, which >>> no longer exists. >> >> I would write this as follows: >> >> entity(chicago:wkshp2002,[prov:type="workshop talks"]) >> activity(ex:download) >> entity(ex:wkshp2002copy) >> wasGeneratedBy(ex:wkshp2002copy,ex:download) >> used(ex:download,chicago:wkshp2002, t1) >> >> wasInvalidated(chicago:wkshp2002, t2) >> >> activity(ex:otherAction) >> used(ex:otherAction, ex:wkshp2002copy, t3) >> >> where t1 < t2 < t3 > > Your examples seems to be conflating the URI that is the identifier > for the entity with the URL from which the content (bunch of bits) > that make up that entity are available. > Isn't it what we want to do in so called "scruffy" provenance. When a resource has a natural identifier (here the URL), we want to reuse it. > I sometimes use URIs for things that are different from the URL from > which their content is available (and for some things that aren't > available through that URL at all like ex:curt -- you might get some > information about me at ex:curt, but you can't actually download me > from there). > I agree with you. We could also have described this entity as follows: entity(urn:uuid:123456,[prov:type="workshop talks",prov:location="http://example.org/wkshp2002"]) The idea of invalidation/expiry still holds, since that entity is no longer at that location after t2. wasInvalidated(urn:uuid:123456, t2) > I also don't really ever use content from the web directly. I always > download it first -- either onto disk or into memory. I then perform > some activity using the thing I downloaded. I don't see the need to > explicitly describe that download activity every single time (though I > could see cases where that would be required) Most of the time I would > just refer to the original entity. > Indeed, we want to allow your kind of usage. > > Anyway, I don't see a need for 'invalidated' for myself, but if > someone else wants to use it, I don't object to it. It does have a > certain symmetry with generation. > > >> Can you expand on this suggestion of prov:SupercededBy? How would >> it work? > > It is really just the inverse of 'wasRevisionOf'. > > Perhaps superseded implies something slightly stronger, in that it > suggests that the version superseded is deprecated in favor of the new > revision. > > We don't really need it since we can just use revision. > OK, thanks for explaining. Luc > Curt >
Received on Tuesday, 13 March 2012 22:26:42 UTC