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Re: Some errors in the discussion of SSN

From: Maxime Lefrançois <maxime.lefrancois.86@gmail.com>
Date: Thu, 22 Sep 2016 09:40:23 +0000
Message-ID: <CALsPASXmFN9ssJHse3t1tYZOOW9HFUmma=qrqccrbWuHJX6gQA@mail.gmail.com>
To: Simon.Cox@csiro.au, kerry.taylor@anu.edu.au
Cc: public-sdw-wg@w3.org
Dear Simon, all,

True, so this means that

RESOLUTION: The ssn:Observation will be redefined as an activity, in line
with O&M Observation

has actually two side effects.

- The first is a side effect within the DOLCE alignment, as described in
https://github.com/w3c/sdw/issues/378 , and requires a decision to be taken
by the group.
- The second might affect any SSN implementation that actually annotated
instances of ssn:Observation with prov metadata, and considered these
instances to be instances of prov:Entity. These implementations will need
to take extra case when migrating to the new version of SSN, else this may
lead to inconsistencies. This should be documented in the REC.

Kind regards,
Maxime Lefrançois

Le jeu. 22 sept. 2016 à 03:53, <Simon.Cox@csiro.au> a écrit :

> Looking at the minutes of the meeting on Tuesday:
>
> https://www.w3.org/2016/09/20-sdw-minutes.html
>
>
>
> Ø  scribe: In PROV an activity can be an entity
>
> Incorrect – there is an axiom in PROV-O that makes them disjoint. See line
> 37 in https://www.w3.org/ns/prov-o
>
>
>
> Ø  kerry: ... Simon made a proposal to just say they're the same but I
> don't think that works.
>
> Must be a misunderstanding here. Rather, I used the PROV alignment to show
> how they (ssn:Observation and om:Observation) are definitely *not* the
> same.
>
>
>
> Ø  kerry: ... I want to take advantage of entity and activity not being
> disjoint
>
> Ø  …
>
> Ø  kerry: No, I don't see a reason for doing that.
>
> Ø  ... In Prov, it's OK to be an activity and an entity
>
> Ø  …
>
> Ø  kerry: The do nothing approach is to say that O&M and SSN Observation
> are the same thing but if you use Prov then you need to recognise that it's
> both Activity and Entity
>
> I don’t think this is a solution. As linked above, in PROV-O (at least)
> prov:Activity and prov:Entity are disjoint.
>
>
>
> Later -
>
> Ø  *RESOLUTION: The ssn:Observation will be redefined as an activity, in
> line with O&M Observation*
>
> OK – I like that resolution of course, though I also acknowledge that
> there is a case for calling the class ‘ActivityOfEstimating’ to capture to
> more general semantics. That should be in the documentation anyway.
>
>
>
> Simon
>
>
>
>
>
> *From:* Krzysztof Janowicz [mailto:janowicz@ucsb.edu]
> *Sent:* Monday, 12 September 2016 12:02 PM
> *To:* Kerry Taylor <kerry.taylor@anu.edu.au>
> *Cc:* public-sdw-wg@w3.org
> *Subject:* Re: fixing ssn
>
>
>
> Hi Kerry,
>
>
> Perhaps all this work was discussed in focus well before you became active
> in the ssn subgroup.
>
>
> I was active from the beginning so I remember out discussions. I just
> wanted to make sure we are not stepping back from our SOSA and
> modularization ideas/work for the new version of the SSN to be
> standardized. Thus, it was unclear to me why we would need changes to the
> old SSN.
>
> Best,
> Krzysztof
>
>
> On 09/11/2016 06:20 PM, Kerry Taylor wrote:
>
> Krzysztof,
> Perhaps all this work was discussed in focus well before you became active
> in the ssn subgroup. It was indeed some time ago, ie more than 6 months
> ago,  but has sat still while the modularity design (yet to be tested by
> experimentation/implementation) ,   SOSA and IoT issues have been given
> more attention.
>
>
>
> We are tasked to bring SSN to a standard, and to simplify and make it
> easier to use, especially by modularisation. An early  decision was made to
> separate dolce, and this was done at that time,  but it became apparent
> that something had gone wrong as we published it  in our FPWD, so I have
> done it again here  from scratch (with minor improvement –e.g. new dolce
> namespace). Given that SSN needs to be broken up (through horizontal and
> vertical modules, as extensively discussed, but with no resolution on how
> big/many of these there would be) , it would be very sad and painful  to do
> that from a base of an SSN now with  unintentional errors in it.
>   Certainly experimentation is needed, but a clean, common  base is surely
> a worthwhile thing to have.
>
>
>
> Some of these problems (see below) were always there (and that is where I
> plan to work next, with the group’s support).   This was discussed briefly
> in the last ssn meeting too, but is also on the agenda for the F2F. I hope
> we can focus there on the next steps for modularisation.
>
>
>
> Does that address your concerns?
>
>
>
> --Kerry
>
> *From:* Krzysztof Janowicz [mailto:janowicz@ucsb.edu <janowicz@ucsb.edu>]
> *Sent:* Monday, 12 September 2016 5:16 AM
> *To:* Kerry Taylor <kerry.taylor@anu.edu.au> <kerry.taylor@anu.edu.au>;
> public-sdw-wg@w3.org
> *Subject:* Re: fixing ssn
>
>
>
> Hi Kerry,
>
> I am bit surprised by your message and what exactly it means. How does
> working on the old SSN align with SOSA and everything else we discussed
> over the past 6 months?
>
> Best,
> Krzysztof
>
> On 09/11/2016 07:14 AM, Kerry Taylor wrote:
>
> I have just “fixed”  the dolce removal from ssn. The version we were
> looking at on webprotege had some errors of uncertain provenance, so I went
> back to SSN  as it was left by the XG here
> https://www.w3.org/2005/Incubator/ssn/ssnx/ssn.owl  (more commonly known
> as http://purl.oclc.org/NET/ssnx/ssn) and removed dolce all over again. I
> also changed the ssn namespace to the new W3c one, and the dolce one to the
> new one http://www.ontologydesignpatterns.org/ont/dul/DUL.owl, and added
> some  annotation comments to reflect this.
>
>
>
> We now have, on github, a new folder sdw/ssn/ssn_separated which contains
> ssn.owl
> <https://github.com/w3c/sdw/blob/gh-pages/ssn/ssn_separated/ssn.owl> and
>        dul-alignment.owl
> <https://github.com/w3c/sdw/blob/gh-pages/ssn/ssn_separated/dul-alignment.owl>
>    . The latter imports dolce but the former does not.   If you look at
> the alignment ontology you can see that ssn has lost a few important things
> that now cannot be said at all and will need to be natively  rebuilt,  in
> addition to the constraints that dolce gave it.
>
>
>
> There are also a good few “bugs” remaining – but these are all original
> ssn bugs. I am thinking of a few things in annotations (including stuff we
> already changed in the web-protégé version) and a lot of typos, and at
> least one place where some class is explicitly subclassed from owl;thing.
>
>
>
> I plan to gradually work through those bugs – and will bring to the
> attention of the list anything that is not either already decided or for
> which there is some choice about what to do.
>
>
>
> If anyone would like to give it a once-over in case I have done something
> stupid, please do.
>
>
>
> --Kerry
>
>
>
>
>
>
>
>
>
> --
>
> Krzysztof Janowicz
>
>
>
> Geography Department, University of California, Santa Barbara
>
> 4830 Ellison Hall, Santa Barbara, CA 93106-4060
>
>
>
> Email: jano@geog.ucsb.edu
>
> Webpage: http://geog.ucsb.edu/~jano/
>
> Semantic Web Journal: http://www.semantic-web-journal.net
>
>
>
>
>
> --
>
> Krzysztof Janowicz
>
>
>
> Geography Department, University of California, Santa Barbara
>
> 4830 Ellison Hall, Santa Barbara, CA 93106-4060
>
>
>
> Email: jano@geog.ucsb.edu
>
> Webpage: http://geog.ucsb.edu/~jano/
>
> Semantic Web Journal: http://www.semantic-web-journal.net
>
>
Received on Thursday, 22 September 2016 09:41:06 UTC

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