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Re: Semantics of events

From: Peter Brooks <peter.h.m.brooks@gmail.com>
Date: Thu, 26 Feb 2015 07:40:13 +0200
Message-ID: <CAFtB7BSogbpDZJw6MRKimnd+o5_zPrnV96a_YBNMj9oSFBDyVw@mail.gmail.com>
To: Xanthor <xanthor@riseup.net>
Cc: semantic-web <semantic-web@w3.org>
An event is something that happens at a particular time. It might be a
recurring event. So, in your example, there might be:

Event: Weekly Comedy Line-up
Time: 19:30
Date: Every Thursday

Then a 'performance' is an instantiation of that event for, say,
Thursday the 26th of February 2015:

Event: Weekly Comedy Line-up
Time: 19:30
Date: 25/02/2015
Director: Joe
EventID: WCL25022015
Performers: http://wcl/WCL25022015

So, yes, a performance is an event, but a specific event.  So, to
answer your question, I'd say B:

th:Performance event:hasEvent :event;
:event a event:Event.

On 24 February 2015 at 03:40, Xanthor <xanthor@riseup.net> wrote:
> Hello
>
> I have an issue with event semantics.
>
> Here is a simple testcase:
>
> Alice wants to go to theatre with Bob, Charly and Debbie.
>
> They all have needs, so Alice will describe everything in RDF.
>
> Bob wants to add the event to his calendar, in order to block his evening.
>
> Charly wants to browse the actors to choose the performance.
>
> Debbie wants to share the performance with friends.
>
>
> Suppose we have an ontology to describe theatre (prefix: th)
>
> We can imagine something like this:
>
> Classes:
>
> th:Play
> th:Performance
>
> Properties:
>
> th:hasPlay
>         domain: th:Performance
>         range: th:Play
>
> th:hasActor
>         domain: th:Performance
>         range: foaf:Person
>
> th:hasPlace
>         domain: th:Performance
>         range: geo:SpatialThing / gn:Feature
>
> th:hasSpectator
>         domain: th:Performance
>         range: foaf:Person
>
> th:hasTheatreDirector
>         domain: th:Performance
>         range: foaf:Person
>
>
> But now, comes the issue of "event" (which will handle the time aspect).
>
> Semantically : is a performance an event, or is a performance related to an
> event?
>
> That is to say, without any existent vocabulary, do we have:
>
> th:Performance rdfs:subClassOf event:Event.
>
> or
>
> th:Performance event:hasEvent :event;
> :event a event:Event.
>
> It seems to me that the first solution is the way to use RDFIcal, and the
> second is more http://motools.sourceforge.net/event/event.html
>
> For me, but I can be wrong:
> The first solution answer directly to Bob testcase, but present semantic
> issues (Is is ok for an event to have a Theatre director? Is it ok for a
> performance to have a ical:prodid?)
>
> The second solution has better semantic, but we need tools to answer Bob
> testcase.
>
> What to you think?
>
>



-- 
Peter Brooks, Fellow in Service Management (FSM)®

Tel: +27 21 447 9752
Mobile: +27 82 717 6 404
Received on Thursday, 26 February 2015 05:41:20 UTC

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