W3C home > Mailing lists > Public > public-sdw-wg@w3.org > March 2017

Re: WG discussion: shall we recommend a "samePlaceAs" property?

From: Krzysztof Janowicz <janowicz@ucsb.edu>
Date: Wed, 15 Mar 2017 19:16:14 -0700
To: Rob Atkinson <rob@metalinkage.com.au>, Stephane Fellah <stephanef@imagemattersllc.com>, Jeremy Tandy <jeremy.tandy@gmail.com>
Cc: Clemens Portele <portele@interactive-instruments.de>, Josh Lieberman <jlieberman@tumblingwalls.com>, Kerry Taylor <kerry.taylor@anu.edu.au>, Bill Roberts <bill@swirrl.com>, SDW WG Public List <public-sdw-wg@w3.org>
Message-ID: <f59ab101-5aba-cb6a-48c8-cd4ec1a61b99@ucsb.edu>
I agree with Rob. Personally, I still do not see the need for the 
relation nor do I fully understand what it should be used for that is 
not covered otherwise; see my previous emails for details. Also, is this 
going to be an isolated samePlaceAs relation or is there a bigger 
picture/ontology here? Finally, owl:sameAs is not all that scary and 
dangerous as it is often being portrait. The problems with owl:sameAs 
were due to mistakes in its early usage of Linked Data. This was clearly 
something that had to be addressed and explained in 2010, but it is not 
that relevant anymore for 2017. OWL:sameAs is one of the most important 
properties on the Linked Data web.

Cheers,
Jano


On 03/15/2017 05:29 PM, Rob Atkinson wrote:
>
> If you are going to use terms that are not explicitly geographic, but 
> relate to similarity, of matching you would be better off using 
> skos:closeMatch, skos:exactMatch etc.
>
> This also allows you to use skos:broader/narrower with transitive 
> versions, and doesnt preclude using a more nuanced geographical 
> relationship that is a subProperty of skos relationships.
>
> This keeps it within the W3C canon, consistent with other OGC usages 
> of SKOS, and is about _relationships between concepts_
>
> If on the other hand the semantics is explicitly about geographic 
> relationship of related but distinct things, then i would suggest 
> using GeoSPARQL or fall back to general advice about re-use of 
> vocabularies.
>
> whatever vocab falls out as BP in the future should have a specific 
> set of functions it supports - and the nuanced differences between the 
> many similar terms it will require will probably only be understood in 
> terms of what the results of such different functions would yield.
>
> Rob
>
>
>
>
> On Thu, 16 Mar 2017 at 10:31 Stephane Fellah 
> <stephanef@imagemattersllc.com <mailto:stephanef@imagemattersllc.com>> 
> wrote:
>
>     Hi,
>
>     During OGC Testbed 10, I raised the issue related to the misuse of
>     owl:sameAs.
>
>     Here the section relevant (12.3.10.1) from the Engineering
>     Report OGC-14-029
>     <https://portal.opengeospatial.org/files/?artifact_id=59336>
>
>     To denote that a place in a gazetteer is the ‘same’ as another one
>     in another gazetteer, the intuitive way is to use the *owl:sameAs*
>     relation. However owl:sameAs has been misused in many existing
>     linked data due to misunderstanding of the rules of inference
>     defined in OWL. The following paper discusses some of the issues
>     with the misuse of owl:sameAs:
>     http://www.w3.org/2009/12/rdf-ws/papers/ws21.A
>
>     A separate property was proposed *gaz:sameLocationAs* instead.
>     This property is transitive and symmetric, so it will infer the
>     mapping on other instances.
>
>
>     Regards
>
>
>     Stephane
>
>
>
>     On Wed, Mar 15, 2017 at 2:46 PM, Jeremy Tandy
>     <jeremy.tandy@gmail.com <mailto:jeremy.tandy@gmail.com>> wrote:
>
>         Yes. It's not place / location domain-specific... but the OSi
>         example shows it being used in the way I was thinking for
>         samePlaceAs.
>
>         Jeremy
>
>         On Wed, 15 Mar 2017 at 18:44, Clemens Portele
>         <portele@interactive-instruments.de
>         <mailto:portele@interactive-instruments.de>> wrote:
>
>             Jeremy,
>
>             doesn’t "similar to" has a different meaning than "same
>             place/location as"?
>
>             Clemens
>
>>             On 15 Mar 2017, at 18:58, Jeremy Tandy
>>             <jeremy.tandy@gmail.com <mailto:jeremy.tandy@gmail.com>>
>>             wrote:
>>
>>             Hi. As agreed during the plenary call on 8-Mar, I have
>>             updated BP14 to include a proposal for "samePlaceAs".
>>
>>             However, having just taken a look at an example
>>             fromdata.geohive.ie <http://data.geohive.ie/>(the "Irish
>>             example" from [1]), I see use of an alternative to
>>             'samePlaceAs':
>>
>>             <http://open.vocab.org/terms/similarTo
>>             <http://open.vocab.org/terms/similarTo>> : "Having two
>>             things that are not the owl:sameAs but are similar to a
>>             certain extent. It is thought of being used where
>>             owl:sameAs is too strong but rdfs:seeAlso is too loose."
>>
>>             In the snippet below you can see the relationship stated
>>             to a dbpedia resource:
>>             <http://data.geohive.ie/resource/county/2AE19629144F13A3E055000000000001>
>>                    rdf:type <http://ontologies.geohive.ie/osi#County> , geo:Feature ;
>>                    rdfs:label "DUBLIN"@en , "DUBLIN" , "Baile Átha Cliath"@ga ;
>>                    _ov:similarTo_  <http://dbpedia.org/resource/County_Dublin> ;
>>                    ... ;
>>                    .
>>             What do you think?
>>
>>             (side-bar discussions already give +1 votes from Linda
>>             and Andrea)
>>
>>             Jeremy
>>
>>             On Tue, 28 Feb 2017 at 21:58 Rob Atkinson
>>             <rob@metalinkage.com.au <mailto:rob@metalinkage.com.au>>
>>             wrote:
>>
>>                 I think we can only point to ad-hoc, and sometimes
>>                 downright bad practices (owl;sameAs pointing to
>>                 google maps interface.... )
>>                 Need to add this to the "open issues" list IMHO
>>
>>                 Rob
>>
>>                 On Wed, 1 Mar 2017 at 06:04 Joshua Lieberman
>>                 <jlieberman@tumblingwalls.com
>>                 <mailto:jlieberman@tumblingwalls.com>> wrote:
>>
>>                     Agreed. There is certainly interest in defining
>>                     qualitative spatial relationships that can be
>>                     asserted and inferred even if geometrically they
>>                     are  imprecise or complex to calculate. However,
>>                     “Place” is not just a position or even a
>>                     geometry, but a type of feature. samePlaceAs
>>                     asserts a much more detailed relationship than
>>                     “collocated” or “notSpatiallyDisjoint”, which may
>>                     be closer to what the proposers were considering.
>>
>>                     —Josh
>>
>>
>>>                     On Feb 28, 2017, at 1:53 PM, Krzysztof Janowicz
>>>                     <janowicz@ucsb.edu <mailto:janowicz@ucsb.edu>>
>>>                     wrote:
>>>
>>>                     Hi,
>>>
>>>
>>>                     Generally speaking I don't think that a
>>>                     predicate as samePlaceAs would be very useful.
>>>                     As far as I recall, Todd Pehle tried to
>>>                     introduce such predicate a few years ago and it
>>>                     was not really used.
>>>
>>>                     First, we would also need samePersonAs,
>>>                     sameEventAs, and so forth, and secondly, the
>>>                     meaning of samePlaceAs remains unclear. The
>>>                     issue is not only that owl:sameAs is more formal
>>>                     in a mathematical sense (which, as stated in
>>>                     this thread, is not always desired), it also
>>>                     related to URIs to each other by stating that
>>>                     both of them point to the same feature (e.g.,
>>>                     the same place in the physical world).  What
>>>                     would samePlaceAs do? If it would relate two
>>>                     places (not URIs), what does it mean for two
>>>                     places to be the same or even similar?
>>>
>>>                     Cheers,
>>>                     Jano
>>>
>>>
>>>
>>>                     On 02/28/2017 02:38 AM, Kerry Taylor wrote:
>>>>                     +1
>>>>                     *From:*Jeremy Tandy [mailto:jeremy.tandy@gmail.com]
>>>>                     *Sent:*Tuesday, 28 February 2017 2:11 AM
>>>>                     *To:*Bill Roberts<bill@swirrl.com>
>>>>                     <mailto:bill@swirrl.com>; SDW WG Public
>>>>                     List<public-sdw-wg@w3.org>
>>>>                     <mailto:public-sdw-wg@w3.org>
>>>>                     *Subject:*Re: WG discussion: shall we recommend
>>>>                     a "samePlaceAs" property?
>>>>                     Thanks Bill.
>>>>                     > Probably a better option would be to propose
>>>>                     it to danbri for addition to schema.org
>>>>                     <http://schema.org/> as a property for things
>>>>                     of type schema:Place ?
>>>>                     You're right that that sounds like a better home.
>>>>                     @danbri: what do you think? (& can you remind
>>>>                     us how we might propose this forschema.org
>>>>                     <http://schema.org/>'s consideration)
>>>>                     Thanks. Jeremy
>>>>                     On Mon, 27 Feb 2017 at 13:43, Bill Roberts
>>>>                     <bill@swirrl.com <mailto:bill@swirrl.com>> wrote:
>>>>
>>>>                         I support creating a samePlaceAs relation.
>>>>                         As well as an IANA link relation, can we
>>>>                         have a URI for it to allow use in RDF?
>>>>                         Possibly related, I see in BP10 that we
>>>>                         refer to ongoing work to update GeoSPARQL -
>>>>                         what's the status of that? Would this
>>>>                         property/relation make sense as part of the
>>>>                         new GeoSPARQL? Maybe the deliberate
>>>>                         vagueness of 'samePlaceAs' might not fit
>>>>                         well with the otherwise generally precise
>>>>                         geosparql relationships.
>>>>                         Probably a better option would be to
>>>>                         propose it to danbri for addition
>>>>                         toschema.org <http://schema.org/>as a
>>>>                         property for things of type schema:Place ?
>>>>                         On 27 February 2017 at 11:44, Jeremy
>>>>                         Tandy<jeremy.tandy@gmail.com
>>>>                         <mailto:jeremy.tandy@gmail.com>>wrote:
>>>>
>>>>                             Hi - for this sprint in development of
>>>>                             the Best Practice document, we're
>>>>                             updating BPs about "linking" and
>>>>                             "vocabularies" ...
>>>>                             On multiple previous occasions (most
>>>>                             recently the London F2F) we've
>>>>                             mentioned that we should propose a
>>>>                             "samePlaceAs" property. In essence, I
>>>>                             think we see this as a subjective
>>>>                             statement (that a human might make)
>>>>                             rather than a mathematical /
>>>>                             topological statement, matching on the
>>>>                             spatial characteristics only.
>>>>                             This addresses the concerns about the
>>>>                             VERY restrictive owl:sameAs. At
>>>>                             TPAC2016, @clemens said that a "relaxed
>>>>                             relationship is better [for
>>>>                             cross-referencing identifiers] (e.g.
>>>>                             samePlaceAs) … but if you _can_ state
>>>>                             owl:sameAs then you should do so …"
>>>>                             [from my notes]
>>>>                             We said at TPAC2015 "samePlaceAs would
>>>>                             be a 'social relationship' - based on
>>>>                             people's perception".
>>>>                             The domain and range should both be
>>>>                             "spatial things" (which definition of
>>>>                             spatial thing do we refer to - the new
>>>>                             one coming from @josh's work or
>>>>                             w3cgeo:SpatialThing?
>>>>                             We're looking to resolve this question
>>>>                             BEFORE the Delft F2F.
>>>>                             WG members: what do you think?
>>>>                             Many thanks, Jeremy
>>>>                             further notes below:
>>>>                             ---
>>>>                             My notes from the most recent
>>>>                             discussion during London F2F are here:
>>>>
>>>>                               * "samePlaceAs"
>>>>                               * it would be an IANA link relation
>>>>                                 identifier
>>>>
>>>>                                   o equivalence at a geographical
>>>>                                     level - without a formal
>>>>                                     definition of that equivalence
>>>>                                   o geography related
>>>>                                   o don't express as a sub-property
>>>>                                     of, for example, "so:matches"
>>>>                                     [<https://files.ifi.uzh.ch/ddis/iswc_archive/iswc/pps/web/iswc2010.semanticweb.org/pdf/261.pdf>https://files.ifi.uzh.ch/ddis/iswc_archive/iswc/pps/web/iswc2010.semanticweb.org/pdf/261.pdf]
>>>>                                     … we're only indicating that
>>>>                                     the _spatial_ properties match
>>>>                                     ... and property hierarchies
>>>>                                     just get complicated to 95% of
>>>>                                     humans
>>>>                                   o not amathematicalstatement
>>>>                                     (like the topological
>>>>                                     relationships)
>>>>                                   o avoid any "mereological"
>>>>                                     confusion [ :) ]
>>>>                                   o nearby? (& other fuzzy
>>>>                                     relationships) ...
>>>>                                     same-place-as is _so_ common
>>>>                                     that we'll deal with it as a
>>>>                                     special case and _not_ cover
>>>>                                     these other spatial
>>>>                                     relationships for now
>>>>                                   o which ontology? IANA Link Relations
>>>>
>>>>                               * ... not used today- so not a _best_
>>>>                                 practice
>>>>                               * ... assert as a [recommended]
>>>>                                 approach to resolve problems we see
>>>>                                 in evidence today- especially
>>>>                                 regarding incorrect use of owl:sameAs
>>>>
>>>>                             ---
>>>>                             And back on the BP call on 9-Nov we said:
>>>>
>>>>                             */jtandy:/*Another aspect to discuss is
>>>>                             the reuse of identifiers ("to keep the
>>>>                             global graph intact").
>>>>
>>>>                             ... But to be able to add additional
>>>>                             information and make it retrievable it
>>>>                             requires a new identifier with a
>>>>                             sameAs-like link to the "known identifier"
>>>>
>>>>                             ... "samePlaceAs"?
>>>>
>>>>                             */eparsons:/*samePlaceAs sounds restrictive
>>>>
>>>>                             */jtandy:/*agrees, we want to avoid the
>>>>                             strong nature of sameAs
>>>>
>>>>                             */ByronCinNZ:/*likes the idea, very
>>>>                             geographic statement. In which ontology
>>>>                             would this reside?
>>>>
>>>>                             */ClemensPortele:/*I think we said it
>>>>                             would be an IANA link relation identifier
>>>>
>>>>                             */jtandy:/*As it does not exist yet, we
>>>>                             cannot claim it is a "best practice"
>>>>
>>>>                             */eparsons:/*I think this problem will
>>>>                             be hard to avoid, but it could be
>>>>                             described as a way to address the issue
>>>>
>>>>                             */ChrisLittle:/*worried about
>>>>                             "samePlaceAs". How does it fit with the
>>>>                             algebra of polygons?
>>>>
>>>>                             */jtandy:/*we don't want to be too specific
>>>>
>>>>                             ... ... at TPAC we had a discussion
>>>>                             about the well-defined topological
>>>>                             relationships
>>>>
>>>>                             */eparsons:/*to get something done
>>>>                             quickly we should try to keep it simple
>>>>
>>>>                             ... ... relationships could be tackled
>>>>                             later
>>>>
>>>>                             */jtandy:/*so we agree that samePlaceAs
>>>>                             is not intended as a mathematical statement
>>>>
>>>>                             <*/ClausStadler_/*>https://files.ifi.uzh.ch/ddis/iswc_archive/iswc/pps/web/iswc2010.semanticweb.org/pdf/261.pdf
>>>>
>>>>                             <*/ClausStadler_/*> "so:matches Two
>>>>                             URIs refer to possibly distinct things
>>>>                             that share all the prop- erties needed
>>>>                             to substitute for each other in some
>>>>                             graphs. Th is property is symmetric but
>>>>                             not necessarily reflexive. so:matches
>>>>                             is a super-property of so:identical ."
>>>>
>>>>                             */ByronCinNZ:/*agrees, and this is
>>>>                             probably the most important of the
>>>>                             topological relationships
>>>>
>>>>                             */ClausStadler_:/*Explains the paper
>>>>                             and "so:matches" reference (see above)
>>>>
>>>>                             */jtandy:/*yes, there is overlap. we
>>>>                             want to focus on the spatial match.
>>>>
>>>>                             */ClausStadler_:/*could be a sub-property
>>>>
>>>>                             */jtandy:/*worried on nesting, maybe it
>>>>                             makes it overcomplicated
>>>>
>>>>                             I agree with the concern
>>>>
>>>>                             <*/eparsons/*> +1
>>>>
>>>>                             */eparsons:/*worried about
>>>>                             complication, too
>>>>
>>>>                             <*/AndreaPerego/*> +1
>>>>
>>>>                             */ByronCinNZ:/*should be a top-level
>>>>                             relationship
>>>>
>>>
>>>
>>>                     -- 
>>>                     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
>>>                     <http://www.semantic-web-journal.net/>
>>
>
>
>
>
>     -- 
>     Stephane Fellah
>     Chief  Knowledge Scientist
>     Image Matters LLC
>     Office: +(703) 669 5510
>     Cell: 703 431 9420
>


-- 
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, 16 March 2017 02:16:52 UTC

This archive was generated by hypermail 2.3.1 : Thursday, 16 March 2017 02:16:52 UTC