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Re: Using rdf:Property class for properties whose URI contains string "time"

From: Krzysztof Janowicz <janowicz@ucsb.edu>
Date: Tue, 28 Mar 2017 15:23:44 -0700
To: Maxime Lefran├žois <maxime.lefrancois@emse.fr>, SDW WG Public List <public-sdw-wg@w3.org>
Message-ID: <912fa99d-f1f2-d3f9-2df3-1bca50119463@ucsb.edu>
Hi,

Yes, but as I tried to describe on the wiki page[1], this is for good 
reasons and we discussed them a few times several months ago. 
PhenomenonTime needs to be able to deal with more complex inputs.

The problem that I was trying to explain was that the currently proposed 
alignment axiom 'ssn:observationResultTime rdfs:subPropertyOf 
sosa:resultTime' is not in OWL2 DL as one is a DataTypeProperty and the 
other one is an ObjectTypeProperty.

The second case 'ssn:observationSamplingTime owl:equivalentProperty 
sosa:phenomenonTime. ' is simple because both are object type properties 
and equivalent anyway.

I liked Raul's proposal (if I understood it correctly) to deprecate 
observationResultTime and observationSamplingTime and then reuse the 
sosa properties resultTime and phenomenonTime in ssn without the need to 
do anything in addition.

Best,
Jano

[1] https://www.w3.org/2015/spatial/wiki/Time_in_SOSA_and_SSN
On 03/28/2017 03:14 PM, Maxime Lefran├žois wrote:
> Dear all,
>
> If I took the minutes correctly today, some of the properties whose 
> URI contains string "time" are object properties and other are 
> datatype properties, so that's not really consistent.
>
> It has been proposed to declare them as instances of rdf:Property 
> instead of having to choose between ObjectProperty and DatatypeProperty.
>
> This could be interesting, these are the side effects I can think of now:
> - we would need to assert these properties are instances of 
> AnnotationProperty, else the ontology would not be OWL DL;
> - no ontology that extends SSN can assert it's also a ObjectProperty 
> or a DatatypeProperty;
> - one cannot make this property be involved in a OWL logical axiom in 
> any possible way, apart from rdfs:domain, rdfs:range, and 
> rdfs:subPropertyOf;
> - still, people can create non-OWL rules ()e.g., SPARQL Construct or 
> SPIN rules) that can generate new knowledge out of some pattern that 
> involves this property.
>
> Best,
> Maxime


-- 
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, 28 March 2017 22:24:25 UTC

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