- From: Anthony Moretti <anthony.moretti@gmail.com>
- Date: Sat, 11 Dec 2021 15:03:26 +1030
- To: Pierre-Antoine Champin <pierre-antoine.champin@ercim.eu>
- Cc: "public-rdf-star@w3.org" <public-rdf-star@w3.org>
- Message-ID: <CACusdfRaWowmmVC==Zy6V7JcqhRqBJ=DK5D1-wHauq8tZP8FsQ@mail.gmail.com>
>
> 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? 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).
[
> 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.
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 captaincy of 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
> 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?
>>
>>
>>
>
Received on Saturday, 11 December 2021 04:34:52 UTC