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

From: Frans Knibbe <frans.knibbe@geodan.nl>
Date: Thu, 16 Mar 2017 14:03:31 +0100
Message-ID: <CAFVDz42bsL=ej5ejkL2PRuA7rJOW1UYw8Qq3nhB9MTKT33VRig@mail.gmail.com>
To: SDW WG Public List <public-sdw-wg@w3.org>
Hello,

There is a established need for having something like 'samePlaceAs'. I
think it is basically what the Subject equality requirement
<https://www.w3.org/TR/sdw-ucr/#SubjectEquality> is about. It often happens
that data about spatial things are held in different systems that use
different models to describe the real world. There is a need to be able to
state that different data representations are about the same spatial thing.
I think the proposed schema:samePlaceAs could do a decent job at meeting
the requirement.

As for limiting the application of the term to geography (mentioned in the
London F2F bullet points in the first message of this thread): Why not make
it applicable to all things spatial? That way we can express things like
'you probably left your keys in the same place as yesterday' or 'the black
hole is in the same place as the supernova that was seen by Kepler in
1604'. The definition of schema:Place seems to strongly hint at geographic
places only. Can we assure that samePlaceAs cab be used as a spatial (not
just geographical) property?

Regards,
Frans

On 16 March 2017 at 07:02, Rob Atkinson <rob@metalinkage.com.au> wrote:

>
> Just a reminder about the semantics of owl:sameAs if you're not fully
> across it it - it means properties can be transitively assigned
>
> A sameAs B
> A costs X
> B isA FrogCollar
>
> means
> A isA FrogCollar
> B costs X
>
> if this is not _exactly_ what you intend, then dont use owl:sameAs
>
>
>
>
> On Thu, 16 Mar 2017 at 13:16 Krzysztof Janowicz <janowicz@ucsb.edu> wrote:
>
>> 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> 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>
>> 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> 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> 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 from data.geohive.ie (the
>> "Irish example" from [1]), I see use of an alternative to 'samePlaceAs':
>>
>> <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> 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> 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>
>> 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
>> <jeremy.tandy@gmail.com>]
>> *Sent:* Tuesday, 28 February 2017 2:11 AM
>> *To:* Bill Roberts <bill@swirrl.com> <bill@swirrl.com>; SDW WG Public
>> List <public-sdw-wg@w3.org> <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 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 for schema.org's consideration)
>>
>> Thanks. Jeremy
>>
>>
>> On Mon, 27 Feb 2017 at 13:43, Bill Roberts <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 to
>>  schema.org as a property for things of type schema:Place ?
>>
>>
>>
>> On 27 February 2017 at 11:44, Jeremy Tandy <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:
>>
>> ---
>>
>>
>>
Received on Thursday, 16 March 2017 13:04:07 UTC

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