- From: Krzysztof Janowicz <janowicz@ucsb.edu>
- Date: Tue, 7 Feb 2017 08:27:09 -0800
- To: Rob Atkinson <rob@metalinkage.com.au>, Armin Haller <armin.haller@anu.edu.au>, "Simon.Cox@csiro.au" <Simon.Cox@csiro.au>, Kerry Taylor <kerry.taylor@anu.edu.au>, "maxime.lefrancois@emse.fr" <maxime.lefrancois@emse.fr>, "public-sdw-wg@w3.org" <public-sdw-wg@w3.org>
- Message-ID: <4d3abcc1-aa2b-3489-5bba-40feb53f8017@ucsb.edu>
> FWIW, my experience of people using O&M is that "Property" was too > ambiguous and people used it in rather arbitrary fashion Agreed. Property is often the top-concept for predicate hierarchies the same way "Thing" works for classes. I would try to avoid using "Property" whenever possible. > So I would suggest the current long-hand name of "ObservableProperty" > is helpful - Agreed. Ant it also makes clear that there are properties that are not observed (see Simon's list before). On 02/06/2017 11:07 PM, Rob Atkinson wrote: > FWIW, my experience of people using O&M is that "Property" was too > ambiguous and people used it in rather arbitrary fashion - strictly is > should relate to a property of the feature being observed, but with > intermediate sampling features, and in general the model of the > observed feature not being available formally this was generally too > hard to unravel - and people tend to use it as a surrogate for the > procedure, or a generalised classification of the subject, or just > their cat's name or something. > > So I would suggest the current long-hand name of "ObservableProperty" > is helpful - and its an opportunity to educate that "observations" may > be performed by physical sensors or via models. IMHO there are > actually a chain of scientific models in play for every physical > sensor, and its all the same thing and a distinction is meaningless. > Sensors are a way to give a shorthand identifier to part of such a > chain, because the sensor construction makes that chain immutable. > > Rob > > > > > > On Tue, 7 Feb 2017 at 13:44 Armin Haller <armin.haller@anu.edu.au > <mailto:armin.haller@anu.edu.au>> wrote: > > Kerry, you seem to be ok with recasting uses of Property in SSN, > as below. I note here that it does not have to be a recasting of > **all**, only where appropriate. There are already several other > subclasses of Property in SSN, e.g. SurvivableProperty, > OperatingProperty etc. which seem to be introduced in SSN to make > it easier for the user of the ontology to know what is meant with > “Property” in a specific use of the class. The same would apply to > ObservableProperty that is introduced in the core, making it > easier for the user to know what this class means, in the absence > of OWL axioms that give the informed user a clue on its intended use. > > *From: *"Simon.Cox@csiro.au" <Simon.Cox@csiro.au> > *Date: *Tuesday, 7 February 2017 at 1:29 pm > *To: *Kerry Taylor <kerry.taylor@anu.edu.au > <mailto:kerry.taylor@anu.edu.au>>, Armin Haller > <armin.haller@anu.edu.au <mailto:armin.haller@anu.edu.au>>, > "janowicz@ucsb.edu <mailto:janowicz@ucsb.edu>" <janowicz@ucsb.edu > <mailto:janowicz@ucsb.edu>>, "maxime.lefrancois@emse.fr > <mailto:maxime.lefrancois@emse.fr>" <maxime.lefrancois@emse.fr > <mailto:maxime.lefrancois@emse.fr>>, "public-sdw-wg@w3.org > <mailto:public-sdw-wg@w3.org>" <public-sdw-wg@w3.org > <mailto:public-sdw-wg@w3.org>> > > > *Subject: *RE: Proposals (was Re: Architecture of SOSA/SSN > integration) : issue-87 only > > Thanks for exploring this Kerry. > > I agree that at least some ‘derivation’ processes fall into our > broad definition of ‘sensing’ and ‘observation’. > > Note that I did hedge the subclassing with the statement > > “These are not necessarily disjoint …”. > > But it is clear that some properties definitely are not > “observable” in any normal sense (e.g. “name”, “owner”, “creator”) > and could never be associated with sensing procedures or instruments. > > So there is a spectrum, but I would suggest that in the SSN layer > at least we really are only interested in Observable Properties, > and it is likely that inventories of these could be usefully > assembled, alongside catalogues of sensors. And that it is useful > to keep these clear of the non-observable properties. > > On subclassing: why is it that you dislike having these in > alignments? Is there a principled reason for this application, or > does subclassing introduce some general difficulty that I’m not > familiar with? > > Simon > > *From:*Kerry Taylor [mailto:kerry.taylor@anu.edu.au > <mailto:kerry.taylor@anu.edu.au>] > *Sent:* Tuesday, 7 February, 2017 12:37 > *To:* Armin Haller <armin.haller@anu.edu.au > <mailto:armin.haller@anu.edu.au>>; janowicz@ucsb.edu > <mailto:janowicz@ucsb.edu>; Maxime Lefrançois > <maxime.lefrancois@emse.fr <mailto:maxime.lefrancois@emse.fr>>; > Cox, Simon (L&W, Clayton) <Simon.Cox@csiro.au>; > public-sdw-wg@w3.org <mailto:public-sdw-wg@w3.org> > *Subject:* RE: Proposals (was Re: Architecture of SOSA/SSN > integration) : issue-87 only > > This subclass means that ssn instance data does not become > sosa-compliant instance data (I would love to have that if you > take all the instances of all the core terms out of an ssn full > instance you also have a usable sosa instance. I know this is > asking a lot… but I want bi-directional interoperability which is > implied by my proposal for integration. I should have spelled this > out earlier – and I suppose it needs some formalisation to be useful. > > In this case if we really need “ObservableProperty)” ( and my own > view is that this is just silly vocabulary, and I’d much rather > keep “property” for O&M compliance anyway, nevertheless I can live > with it) I would like to check again whether **all** SSN uses of > Property could be recast as “Observable property”. They are > certainly not all “Observed” properties, but given an explanation > of what distinguishes “observable” from others kind of properties > I would look at the implications. > > OTOH looking at Simon’s ISO list : > > >-Observation > > >-Assertion (e.g. name, price) > > >-Derivation (e.g. classifications based on combinations of observed > properties) > > >- Inheritance/instantiation (e.g. where a property value is assumed > on the basis of class membership) > > >These are not necessarily disjoint, and it is likely that observable properties are the > most interesting (depending on you epistemological viewpoint) >but > it is useful to recognize that observable properties are a > distinct class. > > It is very clear that in sosa we do **not** want “observable > properties” because we have sensors that are computational > simulations making observations by ‘Derivation” so this may not be > Observable at all. And surely ours can also can be “Assertion” (in > the case the sensor is a human, for example). Maybe even > inheritance/instantiation too. For the latter if we want to > observe that some animal instance (such as animals caught in my > trap) has the property of being a member of some species (e.g. > “Homo Sapiens” ) on the basis of class membership --Why not? Why > should we prohibit that property being observed? > > So this is a really strong reason why we should stick to > “Property” surely! If “Observable property” in this ISO vocab > means anything at all then it must be distinc t from the union > “Property” and so “Property” is what we need! > > I really dislike subclass alignments….and I dislike > equivalentclass almost as much, wherever they actually sit. I > way prefer using the same terms throughout, > > Which I tried to show in my proposal. > > Just catching up here so maybe I missed something. > > Thoughts? > > -Kerry > > *From:*Armin Haller > *Sent:* Tuesday, 7 February 2017 11:49 AM > *To:* janowicz@ucsb.edu <mailto:janowicz@ucsb.edu>; Maxime > Lefrançois <maxime.lefrancois@emse.fr > <mailto:maxime.lefrancois@emse.fr>>; Simon.Cox@csiro.au > <mailto:Simon.Cox@csiro.au>; Kerry Taylor <kerry.taylor@anu.edu.au > <mailto:kerry.taylor@anu.edu.au>>; public-sdw-wg@w3.org > <mailto:public-sdw-wg@w3.org> > *Subject:* Re: Proposals (was Re: Architecture of SOSA/SSN > integration) : issue-87 only > > The sub-class relation would only be introduced in SSN not SOSA. I > should have been more explicit in the second dot-point. The third > dot-point means to say that. > > *From: *Krzysztof Janowicz <janowicz@ucsb.edu > <mailto:janowicz@ucsb.edu>> > *Reply-To: *"janowicz@ucsb.edu <mailto:janowicz@ucsb.edu>" > <janowicz@ucsb.edu <mailto:janowicz@ucsb.edu>> > *Date: *Tuesday, 7 February 2017 at 11:44 am > *To: *Armin Haller <armin.haller@anu.edu.au > <mailto:armin.haller@anu.edu.au>>, Maxime Lefrançois > <maxime.lefrancois@emse.fr <mailto:maxime.lefrancois@emse.fr>>, > "Simon.Cox@csiro.au <mailto:Simon.Cox@csiro.au>" > <Simon.Cox@csiro.au <mailto:Simon.Cox@csiro.au>>, Kerry Taylor > <kerry.taylor@anu.edu.au <mailto:kerry.taylor@anu.edu.au>>, > "public-sdw-wg@w3.org <mailto:public-sdw-wg@w3.org>" > <public-sdw-wg@w3.org <mailto:public-sdw-wg@w3.org>> > *Subject: *Re: Proposals (was Re: Architecture of SOSA/SSN > integration) : issue-87 only > > Not sure, whether I am fully understanding this. > > -ObservableProperty is a subclass of ssn:Property > > > This would violate one of our design principles, namely that SOSA > does not make use of SSN. > > > On 02/06/2017 04:41 PM, Armin Haller wrote: > > It looks like we have a proposal here to resolve issue 87: > https://www.w3.org/2015/spatial/track/issues/87 > > Please let me try to restate what was proposed: > > -ObservableProperty is introduced in SOSA (as is currently > implemented in: > https://github.com/w3c/sdw/blob/gh-pages/ssn/rdf/sosa.ttl) > > -ObservableProperty is a subclass of ssn:Property > > -ObservableProperty is introduced in SSN as well and the > subclass relation to ssn:Property is stated within > > That leaves the door open to have another property in SSN > (and) SOSA concerned with ActuableProperties. > > This should also mean that SSN instances are SOSA instances, > since no axioms in SOSA are violated. > > Is my understanding correct? > > *From: *Maxime Lefrançois <maxime.lefrancois@emse.fr> > <mailto:maxime.lefrancois@emse.fr> > *Date: *Tuesday, 7 February 2017 at 10:14 am > *To: *"Simon.Cox@csiro.au" <mailto:Simon.Cox@csiro.au> > <Simon.Cox@csiro.au> <mailto:Simon.Cox@csiro.au>, > "janowicz@ucsb.edu" <mailto:janowicz@ucsb.edu> > <janowicz@ucsb.edu> <mailto:janowicz@ucsb.edu>, Kerry Taylor > <kerry.taylor@anu.edu.au> <mailto:kerry.taylor@anu.edu.au>, > "public-sdw-wg@w3.org" <mailto:public-sdw-wg@w3.org> > <public-sdw-wg@w3.org> <mailto:public-sdw-wg@w3.org> > *Subject: *Re: Proposals (was Re: Architecture of SOSA/SSN > integration) : issue-87 only > *Resent-From: *<public-sdw-wg@w3.org> > <mailto:public-sdw-wg@w3.org> > *Resent-Date: *Tuesday, 7 February 2017 at 10:15 am > > Yes indeed, this is what I meant. Thanks. > > Le lun. 6 févr. 2017 à 23:50, <Simon.Cox@csiro.au> > <mailto:Simon.Cox@csiro.au> a écrit : > > Øit appears very strange to me to state that a > ssn:property is a sub property of a sosa:ObservableProperty > > ØThis is what can be read at [1] > > Assuming you mean “it appears very strange to me to state > that a ssn:Property is a sub class of a > sosa:ObservableProperty” then I agree. That looks like my > error. > > Simon > > *From:*Maxime Lefrançois [mailto:maxime.lefrancois@emse.fr > <mailto:maxime.lefrancois@emse.fr>] > *Sent:* Monday, 6 February, 2017 17:55 > *To:* janowicz@ucsb.edu <mailto:janowicz@ucsb.edu>; Cox, > Simon (L&W, Clayton) <Simon.Cox@csiro.au> > <mailto:Simon.Cox@csiro.au>; kerry.taylor@anu.edu.au > <mailto:kerry.taylor@anu.edu.au>; public-sdw-wg@w3.org > <mailto:public-sdw-wg@w3.org> > > > *Subject:* Re: Proposals (was Re: Architecture of SOSA/SSN > integration) : issue-87 only > > ØAnd it appears very strange to me to state that > an observable property is a sub property of a > property. > > That was a slip of the tongue, I meant: > > it appears very strange to me to state that a > ssn:property is a sub property of a > sosa:ObservableProperty > > This is what can be read at [1] and is also what I would > model when Phil says: > > >>> Looking at the two definitions, there are differences but > they look > > >>> very minor to my eyes with sosa:ObservableProperty > looking slightly > > >>> more general, so, again, I'd delete ssn:Property. > > [1] - > https://github.com/w3c/sdw/blob/gh-pages/ssn/rdf/ssn-sosa.ttl > > but anyways, +1 in favour of your arguments, and I propose > that: > > - we update sosa-ssn.ttl to reflect what we all agree on; > > - we also consider either to add sosa:ActuableProperty, > or roll back to just sosa:Property. > > Kind regards, > > Maxime > > Not strange actually – not all properties are > observable. In the revision of ISO 19109:2015 we > distinguished between > > -Observation > > -Assertion (e.g. name, price) > > -Derivation (e.g. classifications based on > combinations of observed properties) > > -Inheritance/instantiation (e.g. where a property > value is assumed on the basis of class membership) > > These are not necessarily disjoint, and it is > likely that observable properties are the most > interesting (depending on you epistemological > viewpoint) but it is useful to recognize that > observable properties are a distinct class. > > Yes, not strange at all. I agree with all of Simon's > arguments and we also made them in one of our telco's > half a year ago. > > > > > On 02/05/2017 04:57 PM, Simon.Cox@csiro.au > <mailto:Simon.Cox@csiro.au> wrote: > > ØAnd it appears very strange to me to state that > an observable property is a sub property of a > property. > > Not strange actually – not all properties are > observable. In the revision of ISO 19109:2015 we > distinguished between > > -Observation > > -Assertion (e.g. name, price) > > -Derivation (e.g. classifications based on > combinations of observed properties) > > -Inheritance/instantiation (e.g. where a property > value is assumed on the basis of class membership) > > These are not necessarily disjoint, and it is > likely that observable properties are the most > interesting (depending on you epistemological > viewpoint) but it is useful to recognize that > observable properties are a distinct class. > > Simon > > *From:*Maxime Lefrançois > [mailto:maxime.lefrancois@emse.fr] > *Sent:* Monday, 6 February, 2017 00:22 > *To:* Kerry Taylor <kerry.taylor@anu.edu.au> > <mailto:kerry.taylor@anu.edu.au>; SDW WG Public > List <public-sdw-wg@w3.org> > <mailto:public-sdw-wg@w3.org> > *Subject:* Re: Proposals (was Re: Architecture of > SOSA/SSN integration) : issue-87 only > > +1 for Kerry's arguments. > > And it appears very strange to me to state that an > observable property is a sub property of a property. > > I just changed to sosa:Property instead of > sosa:ObservableProperty in the proposal I am > currently working on. > > + add relations and classes that are missing > > best, > > Maximle > > Le dim. 5 févr. 2017 à 13:44, Kerry Taylor > <kerry.taylor@anu.edu.au > <mailto:kerry.taylor@anu.edu.au>> a écrit : > > PhilA has said > > >>> Looking at the two definitions, there are > differences but they look > > >>> very minor to my eyes with > sosa:ObservableProperty looking slightly > > >>> more general, so, again, I'd delete > ssn:Property. > > This is issue-87. As you can see by my > analysis last November in the tracker > https://www.w3.org/2015/spatial/track/issues/87 , > > (1). A sosa: Observable Property is NOT an O&M > property. The O&M standard has no such term. > > (2) The ssn:Property has the same intended > meaning as an an O&M Property (and, yes it is > an O&M “Property”) and this is explicit by the > annotation within ssn “<dc:source> skos:exactMatch 'property' [O&M]http://www.opengeospatial.org/standards/om </dc:source>” > > > > (3) What is shown in the mapping table is not > the complete annotation for ssn:Property – > just an extract. However that very paragraph > deserves improvement. > > (4) ssn:Property is used in other places > throughout ssn that have nothing to do with > the narrow context associated with Observation > as it is used in SOSA. > > In particular, nothing to do with a > > (5) ssn:Property cannot be deleted --- many, > many things will break. Nor can it be replaced > by sosa:ObservableProperty (see 4). Maybe it > is possible to say sosa:Property > rdfs:SubclassOf ssn:Property but this has its > problems too (ssn instances would not be sosa > instances). A more sophisticated workaround > is required if we head that direction. > > (6) ssn users know it as “Property” . So do > O&M users. Why change, who are we serving? > > (6) OTOH a simple name change in sosa to > “Property” and some clarification on the > rdfs:comments in both places would work – and > then ssn and sosa can use the very same term. > This is the essence of my proposal on the wiki > as a pattern to solve all these many problems. > https://www.w3.org/2015/spatial/wiki/Proposals_for_rewriting_SSN#Compromise_Proposal_6_made_by_Kerry_January_2017 > > In this case the rdfs:comment suggested by > Armin looks very close but I prefer > abbreviated as follows (due to (4) ) “An > observable quality of a real world phenomena > (thing, person, event, etc.) “ or here is > another idea that I propose “An observable > quality of a real world phenomena (object, > person, or event), typically a > FeatureOfInterest” . That works well in the > context for my proposal that also shows how to > use it in the simple core. > > -Kerry > > Dr Kerry Taylor > > Associate Professor (Data Science) > > Research School of Computer Science > > ANU College of Engineering and Computer Science > > Canberra ACT 2601 Australia > > +61 2 6125 8560 <tel:+61%202%206125%208560> > > -- > > Krzysztof Janowicz > > > > Geography Department, University of California, Santa Barbara > > 4830 Ellison Hall, Santa Barbara, CA 93106-4060 > > > > Email:jano@geog.ucsb.edu <mailto:jano@geog.ucsb.edu> > > Webpage:http://geog.ucsb.edu/~jano/ > <http://geog.ucsb.edu/%7Ejano/> > > 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 <mailto:jano@geog.ucsb.edu> > > Webpage:http://geog.ucsb.edu/~jano/ <http://geog.ucsb.edu/%7Ejano/> > > 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 Tuesday, 7 February 2017 16:27:48 UTC