Re: OnAgainOffAgain relations - beyond celeb marriage: Org membership

On 11/12/2021 05:33, Anthony Moretti wrote:
>
>     Idea:
>
>     define a schema:realizationOf property, whose domain is
>     schema:Event and range is rdf-star:Triple (with an inverse
>     property schema:realization). The above could be expressed in
>     JSON-LD-star [1] as follows:
>
>     {
>         "@context": "https://schema.org/" <https://schema.org/>,
>         "@type": "Event",
>         "realizationOf": { "@id": {
>             "@id": "#bowls_club",
>             "captain": "#bob"
>         }},
>         "startDate": "01-01-2019",
>         "endDate": "31-12-2019"
>     }
>
> That works. Although when stating this I think the start and end dates 
> should also be in the RDF-star triple. If the dates aren't there then 
> the event is adding information to the triple, whereas I think the 
> intention of "realization of" is to show a one-to-one mapping, is that 
> right?
no, see below
> If the intention isn't a one-to-one mapping then it's sort of saying 
> "instance of", where the only thing differentiating instances is the 
> time period, which implies that all standard RDF triples without start 
> and end times are implicit *types* of events (also makes sense to me).

yes, this is the idea behind my examples.

Note that, by design, RDF-star does not support the one-to-one mapping, 
because quoted triples are (roughly) like IRIs or literals: they 
represent the *same thing* everywhere they appear. This is discussed in 
the CG report [1].

>
>     [
>         a :TenuredOfficeEvent ;
>         schema:name "Presidency of the United States"@en ;
>         :hasTermStartYear "1885"^^xsd:gYear ;
>         :hasTermEndYear "1889"^^xsd:gYear ;
>         :hasOfficer dbpedia:Grover_Cleveland
>     ] schema:author [
>                           a schema:Person;
>                           schema:worksFor
>     <https://www.whitehouse.gov/#this>
>                       ] ;
>        schema:publisher <https://www.whitehouse.gov/#this> .
>
>     [
>         a :TenuredOfficeEvent ;
>         schema:name "Presidency of the United States"@en ;
>         :hasTermStartYear "1893"^^xsd:gYear ;
>         :hasTermEndYear "1897"^^xsd:gYear ;
>         :hasOfficer dbpedia:Grover_Cleveland
>     ] schema:author [
>                           a schema:Person;
>                           schema:worksFor
>     <https://www.whitehouse.gov/#this>
>                       ] ;
>        schema:publisher <https://www.whitehouse.gov/#this> .
>
>     ## Turtle End ##
>
>     Key point:
>
>     No reification required, courtesy of RDF's fundamental essence :)
>
>     Kingsley
>
>
> That works, although it's less flexible because it interleaves 
> concepts. For it to be fully understood a reasoner has to understand 
> "Presidency of the United States" rather than simpler concepts that 
> can be reused like "is President of" and "United States". Composition 
> over inheritance 
> <https://en.wikipedia.org/wiki/Composition_over_inheritance> could 
> probably make the design simpler, but yeah it works for sure too.

Exactly. What I like about the "realization" pattern (or any similar 
pattern involving quoted triples) is that it keeps a link between the 
complex construct (the event) and the simple triple (asserted or not).

   pa

[1] https://w3c.github.io/rdf-star/cg-spec/editors_draft.html#occurrences


>
> Personally, modeling would be much cleaner and more complete if all 
> statements could have start and end time positions, and ideally a 
> location position, then every statement has the _option_ of being 
> scoped in space and time. The modeling of recurring events then falls 
> out of that and people could either do it Kingsley's way with events 
> or just use statements with start and end times, whichever they prefer.


>
> Regards
> Anthony
>
>
> On Sat, Dec 11, 2021 at 3:43 AM Pierre-Antoine Champin 
> <pierre-antoine.champin@ercim.eu> wrote:
>
>
>     On 10/12/2021 04:05, Anthony Moretti wrote:
>>     Agreeing with Dan here, you could argue that any instance of
>>     schema:Event is also an example.
>     +1
>>
>>     Taking Simon's example:
>>     Bob - is captain of - Bowls Club - Jan 1, 2019–Dec 31, 2019
>>     Bob - is captain of - Bowls Club - Jan 1, 2020–Dec 31, 2020
>>
>>     Seems equivalent to:
>>
>>     schema:Event
>>     Bob's captaincy of Bowls Club 2019
>>     startTime: Jan 1, 2019
>>     endTime: Dec 31, 2019
>>
>>     schema:Event
>>     Bob's captaincyof Bowls Club 2020
>>     startTime: Jan 1, 2020
>>     endTime: Dec 31, 2020
>
>     Idea:
>
>     define a schema:realizationOf property, whose domain is
>     schema:Event and range is rdf-star:Triple (with an inverse
>     property schema:realization). The above could be expressed in
>     JSON-LD-star [1] as follows:
>
>     {
>         "@context": "https://schema.org/" <https://schema.org/>,
>         "@type": "Event",
>         "realizationOf": { "@id": {
>             "@id": "#bowls_club",
>             "captain": "#bob"
>         }},
>         "startDate": "01-01-2019",
>         "endDate": "31-12-2019"
>     }
>
>     (assuming that "realization" and "captain" are part of the
>     schema.org <http://schema.org> context)
>
>     The annotation syntax could also be used, if bob was *currently*
>     captain of the club:
>
>     {
>         "@context": "https://schema.org/" <https://schema.org/>,
>         "@id": "#bowls_club",
>         "captain": {
>             "@id": "#bob",
>             "@annotation": {
>                 "realization": {
>                     "@type": "Event",
>                     "startDate": "01-01-2021",
>                     "endDate": "31-12-2021"
>                 }
>             }
>         }
>     }
>
>       pa
>
>     [1] https://json-ld.github.io/json-ld-star/

>
>
>     PS: in case anyone is wondering, the Turtle-star corresponding to
>     the above JSON-LD-star would be
>
>     [] a s:Event ;
>         s:realizationOf << <#bowls_club> s:captain <#bob> >> ;
>         s:startDate "01-01-2019"^^s:Date ;
>         s:endDate "31-12-2019"^^s:Date.
>
>     and
>
>     <#bowls_club> s:captain <#bob> {|
>         s:realization [
>             a s:Event ;
>             s:startDate "01-01-2019"^^s:Date ;
>             s:endDate "31-12-2019"^^s:Date
>         ]
>     |}.
>
>>
>>     It seems natural to me that every triple should have start and
>>     end time positions and possibly also a location position. The
>>     above examples seem to me like different ways of saying the same
>>     thing, albeit the first has more structure. You could argue that
>>     schema:Event is just a convenience type for statements with
>>     temporal data.
>>
>>     YAGO knowledge base is a good example:
>>     https://www.sciencedirect.com/science/article/pii/S0004370212000719

>>
>>     Regards
>>     Anthony
>>
>>
>>     On Fri, Dec 10, 2021 at 8:20 AM Cox, Simon (L&W, Clayton)
>>     <Simon.Cox@csiro.au> wrote:
>>
>>         Captain of the bowls club is another example.
>>
>>         (I was in one of these the other day admiring the wooden
>>         honour boards – the same names come up repeatedly but not
>>         necessary sequentially.)
>>
>>         *From:*Dan Brickley <danbri@google.com>
>>         *Sent:* Thursday, 9 December, 2021 22:57
>>         *To:* public-rdf-star@w3.org
>>         *Subject:* OnAgainOffAgain relations - beyond celeb marriage:
>>         Org membership
>>
>>         The celebrity re-marriage example is interesting and real,
>>         but may look a bit artificial or cornercase. A similarly
>>         structured situation is much more common - membership of
>>         organizations.
>>
>>         For example one organization being a member of another.
>>
>>         https://www.wikidata.org/wiki/Q51698517 is the International
>>         Fact Checking Network (IFCN). It has a notion of membership
>>         grounded in review of members w.r.t. their official principles.
>>
>>         Verified signatories are e.g.
>>         https://www.wikidata.org/wiki/Q30325238 (Full Fact). There
>>         are some organizations such as Snopes
>>         (https://www.wikidata.org/wiki/Q2287154) who were once
>>         members (verified signatories) but who are not currently.
>>
>>         Wikidata uses annotations on a
>>         https://www.wikidata.org/wiki/Property:P463 edge between IFCN
>>         and Snopes to give start/end times (
>>
>>         15 April 2017, 5 June 2019). It also points to
>>         evidence/source document.
>>
>>         As far as I know Snopes have only been members once, but if
>>         they were to rejoin it seems Wikidata could accomodate the
>>         task of representing this.
>>
>>         Until I learn a better name for it that isn't too grandiose,
>>         I am calling these "on again, off again" relationships, in
>>         honour of the celebrity marriage/divorce usecase.
>>
>>         Dan
>>
>>         p.s. another example, not quite notable enough for Wikidata
>>         to record:
>>
>>         I (https://www.wikidata.org/entity/Q56641640) have twice been
>>         a member of https://www.wikidata.org/wiki/Q7552326 (AISB -
>>         Society for the Study of Artificial Intelligence and
>>         Simulation of Behaviour).  But then I have multiple times
>>         lived in the U.K., or been in various restaurants; how do we
>>         scope RDF-Star's applicability? Which of these are reasonable
>>         places it could be used for time-scoped relationships?
>>