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Re: local vs global restrictions on properties - was RE: ssn "not machine readable"

From: Frans Knibbe <frans.knibbe@geodan.nl>
Date: Thu, 19 May 2016 10:18:45 +0200
Message-ID: <CAFVDz40_Aod9NSAjRDF-2H70ELNX1Hh1AVTXCM891PvFdnOx8A@mail.gmail.com>
To: Simon Cox <Simon.Cox@csiro.au>
Cc: Kerry Taylor <kerry.taylor@anu.edu.au>, Krzysztof Janowicz <janowicz@ucsb.edu>, s.kolozali@surrey.ac.uk, SDW WG Public List <public-sdw-wg@w3.org>
Hello all,

I am trying to follow this interesting discussion that seems to affect all
ontology development (SSN, time, coverage and possibly the putative spatial
ontology). The OWL Restrictions document
<http://www.cs.vu.nl/~guus/public/owl-restrictions/> referenced by Kerry is
helpful for explaining local vs. global restrictions. But I am lost at
guarded restrictions. Is there a document on the web that explains what
guarded restrictions are, and why they are useful?

Regards,
Frans

2016-05-19 2:08 GMT+02:00 <Simon.Cox@csiro.au>:

> I have also encountered this issue in the context of revising OWL-Time.
>
>
>
> The 2006 version has domain/range specified for almost properties.
>
> This effectively prevents some useful predicates (e.g. :before, :after,
> :inside) from being reused in externally defined applications unless all
> the externally defined classes are sub-classed from :TemporalEntity (or
> more strictly, use of these properties would entail subsumption from
> :TemporalEntity).
>
>
>
> In the OGC view of the world, features _*have*_ geometry properties, they
> are not subclassed from geometry classes. If we assume the same
> relationship with Temporal Entities, then we have to decouple temporal
> properties from only being associated with Temporal Entities.
>
>
>
> I would propose to remove some of the global rdfs:domain restrictions in
> particular, and add local cardinality constraints instead (where they are
> not already present).
>
>
>
> Simon
>
>
>
>
>
> *From:* Kerry Taylor [mailto:kerry.taylor@anu.edu.au]
> *Sent:* Wednesday, 18 May 2016 10:21 AM
> *To:* janowicz@ucsb.edu; s.kolozali@surrey.ac.uk
> *Cc:* public-sdw-wg@w3.org
> *Subject:* RE: ssn "not machine readable"
>
>
>
> I get this now. SSN as it is now, usually uses  “local” domain and range
> constraints (formulated as restrictions) instead of  “global “ ones
> (formulated using the rdfs:domain and rdfs:range) properties. I believe it
> is actually quite careful about constraining object properties properly
> (maybe even too careful) and does it in  a best practice machine-readable
> OWL style.
>
>
>
> Personally, I very much support the SSN-as-it-is-now style of object
> property constraints, but I am aware of a growing trend to do it the other
> way in simple “linked-data” ontologies.  This article includes a brief
> rationale  http://www.cs.vu.nl/~guus/public/owl-restrictions/ for the SSN
> “local” way.
>
>
>
> This deserves more thought as part of the “simplification” and
> “modularisation” and “RDFS core” discussions…
>
> Kerry
>
>
>
>
>
>
>
>
>
> *From:* Krzysztof Janowicz [mailto:janowicz@ucsb.edu <janowicz@ucsb.edu>]
> *Sent:* Wednesday, 18 May 2016 8:54 AM
> *To:* s.kolozali@surrey.ac.uk; Kerry Taylor <kerry.taylor@anu.edu.au>
> *Cc:* public-sdw-wg@w3.org
> *Subject:* Re: ssn "not machine readable"
>
>
>
> Hi,
>
> I do not understand how the lack of global domain and range restrictions
> make SSN not machine readable. Also, there are many good reasons not to
> include global range and domain restrictions (and for adding guarded
> restrictions instead).
>
> Best,
> Krzysztof
>
> On 05/17/2016 03:39 PM, s.kolozali@surrey.ac.uk wrote:
>
> Hi Kerry,
>
>
>
>     This was a problem that I had faced when I had to parse and map the
> SSN ontology (along with a many other ontologies) into SAOPY library that I
> have developed (
> http://iot.ee.surrey.ac.uk/citypulse/ontologies/sao/saopy.html). What I
> observed back then was the SSN ontology was missing all the domain and
> range restrictions for object properties. I had stated this problem to you
> in an e-mail and you had told me that it was simply due to the fact that
> "SSN ontology is using global restrictions instead of local restrictions".
> To solve this issue, I had to add all the domain and range restrictions of
> object properties one by one by going through and reading the comments in
> the SSN ontology. I am happy to send my local SSN copy to you "if you are
> interested in", which can save you a lot of time.
>
>
>
> An excerpt the SSN ontology:
>
>     <!-- http://purl.oclc.org/NET/ssnx/ssn#detects -->
>
>
>
>     <owl:ObjectProperty rdf:about="&ssn;detects">
>
>         <rdfs:label>detects</rdfs:label>
>
>         <rdfs:seeAlso>
> http://www.w3.org/2005/Incubator/ssn/wiki/SSN_Skeleton#Skeleton
> </rdfs:seeAlso>
>
>         <rdfs:comment>A relation from a sensor to the Stimulus that the
> sensor can detect.
>
> The Stimulus itself will be serving as a proxy for (see isProxyOf) some
> observable property.</rdfs:comment>
>
>         <rdfs:isDefinedBy>http://purl.oclc.org/NET/ssnx/ssn
> </rdfs:isDefinedBy>
>
>     </owl:ObjectProperty>
>
>
>
>
>
> An excerpt from my local copy of the SSN ontology:
>
>     <!-- http://purl.oclc.org/NET/ssnx/ssn#detects -->
>
>
>
>     <owl:ObjectProperty rdf:about="&ssn;detects">
>
>         <rdfs:label>detects</rdfs:label>
>
>         <rdfs:seeAlso>
> http://www.w3.org/2005/Incubator/ssn/wiki/SSN_Skeleton#Skeleton
> </rdfs:seeAlso>
>
>         <rdfs:comment>A relation from a sensor to the Stimulus that the
> sensor can detect.
>
> The Stimulus itself will be serving as a proxy for (see isProxyOf) some
> observable property.</rdfs:comment>
>
>         <rdfs:isDefinedBy>http://purl.oclc.org/NET/ssnx/ssn
> </rdfs:isDefinedBy>
>
>         <rdfs:domain rdf:resource="&ssn;Sensor"/>
>
>         <rdfs:range rdf:resource="&ssn;SensorInput"/>
>
>         <rdfs:range rdf:resource="&ssn;Stimulus"/>
>
>     </owl:ObjectProperty>
>
>
>
> Although it sounds like a fairly simple and straight forward issue, it
> causes lots of issues when one attempts to parse and use the SSN ontology
> in an automated way. The text written in the form of rdfs:comments are
> helpful for people but local restrictions are more helpful for machine
> interpretation.
>
>
>
> Cheers,
>
>
>
> Sefki Kolozali
> Research Fellow
> Institute for Communication Systems (ICS), home of the 5G Innovation
> Centre
> University of Surrey
> Guildford, Surrey, GU2 7XH, United Kingdom
> Tel: +44 (0)1483 689490
>
> E-mail: s.kolozali@s <s.kolozali@qmul.ac.uk>urrey.ac.uk
>
> http://www.surrey.ac.uk/ics/ <http://www.surrey.ac.uk/ccsr/>
>
>
>
>
>
>
>
>
>
>
>
> On 17 May 2016, at 23:11, Kerry Taylor <kerry.taylor@anu.edu.au> wrote:
>
>
>
> Hi Sefki,
>
>
>
> Can you please explain further what you meant about failure of  “machine
> readability” with ssn as raised in the meeting today? Before that, can you
> do your test with this ssn herehttps://www.w3.org/ns/ssn/  as it seems
> likely to me that dul could have been the source of trouble and this is the
> new  (FPWD) version with dul removed.
>
>
>
> 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
>
>
Received on Thursday, 19 May 2016 08:19:23 UTC

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