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15:33:08 <RRSAgent> logging to https://www.w3.org/2024/03/28-rdf-star-irc
15:33:53 <TallTed> TallTed has changed the topic to: RDF-Star WG -- 2024-03-28 Agenda: https://www.w3.org/events/meetings/5ecc5c5f-5cd2-410c-b97c-6b13c6b843f1/20240328T110000/
15:34:23 <TallTed> RRSAgent, draft minutes
15:34:25 <RRSAgent> I have made the request to generate https://www.w3.org/2024/03/28-rdf-star-minutes.html TallTed
15:34:28 <TallTed> RRSAgent, make logs public
15:35:53 <TallTed> meeting: RDF-star WG biweekly technical meeting
15:35:53 <TallTed> previous meeting: https://www.w3.org/2024/03/22-rdf-star-minutes.html
15:35:54 <TallTed> next meeting: https://www.w3.org/2024/03/29-rdf-star-minutes.html
15:35:54 <TallTed> chair: ?chair?
15:35:54 <TallTed> scribe: ?scribe?
15:35:54 <TallTed> agenda: https://www.w3.org/events/meetings/5ecc5c5f-5cd2-410c-b97c-6b13c6b843f1/20240328T110000/
15:35:55 <agendabot> clear agenda
15:35:55 <agendabot> agenda+ Discuss if a single id can reify more than one triple
15:36:01 <TallTed> RRSAgent, draft minutes
15:36:02 <RRSAgent> I have made the request to generate https://www.w3.org/2024/03/28-rdf-star-minutes.html TallTed
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16:00:03 <Tpt> regrets+ Tpt
16:00:05 <TallTed> present+
16:00:11 <ktk> present+
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16:01:10 <gkellogg> present+
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16:01:17 <eBremer> present+
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16:01:32 <gtw> present+
16:01:39 <ora> present+
16:01:43 <ora> chair: ora
16:01:45 <tl> present+
16:01:47 <pchampin> present+
16:02:08 <TallTed> RRSAgent, draft minutes
16:02:09 <RRSAgent> I have made the request to generate https://www.w3.org/2024/03/28-rdf-star-minutes.html TallTed
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16:02:44 <niklasl> present+
16:02:54 <TallTed> s/chair: ora//
16:02:54 <TallTed> s/?chair?/ora/
16:03:35 <gkellogg> scribe+
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16:04:14 <olaf> present+
16:04:16 <TallTed> Zakim, open first item
16:04:16 <Zakim> I don't understand 'open first item', TallTed
16:04:21 <TallTed> Zakim, next agenda item
16:04:21 <Zakim> agendum 1 -- Discuss if a single id can reify more than one triple -- taken up [from agendabot]
16:04:25 <gkellogg> ora: discussing if a single reifier can reify more than one triple.
16:04:45 <TallTed> RRSAgent, draft minutes
16:04:46 <RRSAgent> I have made the request to generate https://www.w3.org/2024/03/28-rdf-star-minutes.html TallTed
16:05:11 <gkellogg> ... I've stayed back from conversations up until now, but I need to take the chair hat off and speak as a member:
16:05:37 <gkellogg> ... I have a few points that trouble me about allowing a single reifier reify more than one triple.
16:06:08 <Souri> Souri has joined #rdf-star
16:06:14 <gkellogg> ... It's been 27 years since I started working on Pix-NG, which became RDF. In that 27 years, it's been an uphill battle to explain it to people.
16:06:19 <Souri> present+
16:06:38 <gkellogg> ... Some people get it right away, but for a lot it is difficult to explain how it works and what it does.
16:06:51 <gkellogg> ... This topic could make it a lot harder to explain.
16:07:33 <gkellogg> ... Regardless of how useful it might be to have multiple triples reified, it remains confusing for people, which worries me.
16:07:56 <gkellogg> ... Another thing is the distinction between named graphs and sets of triples reified.
16:08:31 <gkellogg> ... I find it difficult to explain the distinction between named graphs and multiple reifiers.
16:08:46 <gkellogg> ... On this list, I think we're mixing domain modeling and the fundamental RDF mechanisms.
16:09:08 <gkellogg> ... We haven't discussed what it would man say for SPARQL, or how to implement things.
16:09:10 <TallTed> q+
16:09:15 <tl> q+
16:09:27 <gkellogg> ack TallTed
16:09:29 <ora> ack TallTed
16:09:30 <gtw> q+
16:09:51 <gkellogg> TallTed: To say you can have only one object for a given predicate breaks other assumptions in RDF.
16:10:43 <gkellogg> ... RDF allows you to say anything about anything, I would expect it to be okay to have multiple, otherwise you'd have to say that the last utterance wins, and given that there is no order, it breaks query.
16:11:12 <gkellogg> ... I don't think the restriction is viable. How to handle without it may require something else.
16:11:19 <ora> ack tl
16:11:19 <pchampin> If this is meant to be a strong restriction (as in "forbidden in the abstract syntax"), I'm strong +1 with TallTed
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16:11:25 <gkellogg> ... It may turn into a reification of a set of triples, which is close to a graph,
16:11:40 <niklasl> +1 to what Ted said
16:11:44 <Dominik_T> present+
16:11:57 <pchampin> but the restriction could be softer, just like rdf:first is "meant" to be functional, but this is not enforced by the abstract syntax
16:12:13 <gkellogg> tl: You said Named Graphs should be out of the picture, but they come back when you talk about sets of triples. If named graphs are in the picture, I'd go back to my nested named graphs proposal.
16:12:26 <gkellogg> ... How do you explain that to people?
16:12:53 <gkellogg> ... You'll get questions because named graphs are optimized for multiple triples, and reification is not.
16:13:07 <gkellogg> ... Two different but similar mechanisms will be difficult to explain.
16:13:35 <gkellogg> ... Doerte explained how some cases require multiple triples to be reified.
16:13:52 <gkellogg> ... We should talk about meaning, not about how it's encoded.
16:14:29 <niklasl> +1 to Thomas too. (We need to talk about what it *means*.)
16:14:31 <gkellogg> ... It's going to be complicated to explain, Once you get further into RDF it becomes complicated.
16:14:33 <ora> ack gtw
16:15:03 <gkellogg> gtw: I think that once we switch to using the "reifies" description it changes the assumptions.
16:15:28 <gkellogg> ... We're getting away from our charter which talks about statements on statements, which was about single triples.
16:15:41 <niklasl> q+
16:15:45 <gkellogg> ... It feels like an entirely different thing than what I thought the WG was aiming for.
16:16:02 <gkellogg> ora: The reason I brought up Named Graphs is because they're part of RDF.
16:16:14 <gkellogg> ... These two things look the same, but they're not.
16:16:17 <ora> ack niklasl
16:16:24 <Souri> q+
16:17:01 <gkellogg> niklasl: I think the discussion started by Thomas is pertinent. I've had confusing discussions about RDF-star too.
16:17:31 <gkellogg> ... We need to dig into the use cases; the original use case with quoted triples it was unclear if it was used as a subject, which was shown to not work out.
16:17:39 <TallTed> Zakim, who's here?
16:17:39 <Zakim> Present: TallTed, ktk, gkellogg, pfps, eBremer, gtw, ora, tl, pchampin, niklasl, olaf, Souri, Dominik_T
16:17:42 <Zakim> On IRC I see Dominik_T, Souri, olaf, niklasl, tl, ora, eBremer, pfps, gkellogg, RRSAgent, Zakim, pchampin, TallTed, joraboi445, AnthonySpencer, csarven, gtw, smoothsalt, Timothe,
16:17:42 <Zakim> ... SintayewGashaw, VladimirAlexiev, ktk, agendabot, Tpt, gb, driib5, rhiaro
16:17:55 <gkellogg> ... Thomas talked about using named graphs.
16:18:18 <gkellogg> ... I wonder if we need to talk about one quoted triple, what was wrong with existing reification?
16:18:40 <gkellogg> ... The assumptions were that it wasn't good enough, as it's just one kind of reification (at statement).
16:19:29 <gkellogg> ... Because we have S/P/O, the old style is only one triple, but I think it's been shown that a reification isn't necessarily tied to just one abstract triple.
16:20:01 <TallTed> present+ enrico, kurt_cagle
16:20:02 <gkellogg> ... As with anything, the identifier denotes something, and a reifier that donotes multiple triples denotes something.
16:20:08 <TallTed> RRSAgent, draft minutes
16:20:10 <RRSAgent> I have made the request to generate https://www.w3.org/2024/03/28-rdf-star-minutes.html TallTed
16:20:16 <gkellogg> ... What is being reified depends on the domain of discourse.
16:20:46 <gkellogg> ... It could be an observation or an event. When it's an event, it's almost guaranteed that it reifies more than one triple.
16:21:17 <gkellogg> ... Both :a :marries :b and :b :marries :a are reified by the event of marriage.
16:21:33 <gkellogg> ... I think that it can work.
16:21:34 <ora> ack Souri
16:21:37 <pchampin> present+ Kurt_Cagle, Enrico
16:21:38 <Souri>    if a domain says=> :Single owl:disjointWith :Married, then this is NOT valid=> GRAPH :g { :s rdf:type :Married, :Single } .  BUT this is valid=> :e rdf:reifies <<( :s rdf:type :Married )>>, <<( :s rdf:type :Single )>> .
16:22:35 <gkellogg> Souri: If you have a named graph, you cannot create a valid dataset with contradictory statements, but with reification, you can.
16:23:15 <pchampin> Souri: the graph between curly brackets is inconsistent (with the ontology), but the dataset it self is neither consistent nor inconsistent -- it does not have a standard formal semantics
16:23:17 <gkellogg> ... Each statement is independent, but the same reifier reifies two different triples (separately, not as a set).
16:23:29 <gkellogg> ... This allows us more expressivity.
16:24:09 <gkellogg> ... Our goal is to be able to support edges in all generality, including some things supported by LPGs and others that aren't.
16:24:22 <ora> q+
16:24:46 <gkellogg> ... It allows me to talk about how two edges are related.
16:25:18 <gkellogg> ... We need to focus on these things to provide more power in RDF 1.2.
16:25:40 <gkellogg> ... If we should allow the same reifier to reify more than one triple is up for debate.
16:26:09 <ora> ack ora
16:26:15 <gkellogg> ... But, we need to provide some edge support with full generality, so that people can describe the relationship between edges as well as normal edge properties.
16:26:49 <gkellogg> ora: We're not really discussion OWL, but your example could be taken as an argument for or against the multiple-reifier case.
16:27:02 <niklasl> q+
16:27:06 <gkellogg> ... I don't understand what your example supports.
16:27:54 <gkellogg> Souri: In that example (there's another too), there are two options. If you're using a single reifier to reify two inconsistent triples, it could be confusing if you don't come at it from RDF.
16:28:31 <gkellogg> ... If we said :e1 reifies s:Married, and :e2 refies s:Single, it might be simpler to use a multi-reifier.
16:28:32 <tl> q+
16:28:46 <gkellogg> ... I think it would be easier for the user if it is single.
16:28:57 <ora> ack niklasl
16:29:03 <TallTed> regrets+  Felix_Sasaki, Doerthe_Arndt
16:29:03 <gkellogg> ... One triple pattern per refier is simpler for users to understand.
16:29:12 <TallTed> RRSAgent, draft minutes
16:29:14 <RRSAgent> I have made the request to generate https://www.w3.org/2024/03/28-rdf-star-minutes.html TallTed
16:29:23 <niklasl> ex:Fact a owl:Class ; rdfs:subClassOf [ a owl:Restriction; owl:onProperty rdf:reifies ; owl:cardinality 1 ] .
16:29:32 <gkellogg> niklasl: Just to reiterate, I think the reifier type could ...
16:30:02 <gkellogg> ... For a given type, a reifier may reify only a single triple, in other cases, it may reify multiple.
16:30:27 <gkellogg> ... To test this, we need to look at use cases.
16:30:38 <ora> ack tl
16:30:44 <gkellogg> ... Maybe we realize rdf:Statement was good enough all along, but I doubt it.
16:31:15 <gkellogg> tl: Perhaps it makes sense for events, but what about other things?
16:31:43 <gkellogg> ... Why do you think its easier with only a single triple?
16:32:18 <ora> q+
16:32:22 <gkellogg> ... It's frustrating to both have named graphs but not use them for something they're suited for.
16:32:33 <ora> ack ora
16:33:28 <gkellogg> ora: To be clear, I went through an exercise of explaining it to people, to identify reification vs a set of triples becomes confusing.
16:33:56 <gkellogg> ... We have to have a super clear description of what this does. This could go off the rails if we make it even more complicated.
16:34:13 <tl> q?
16:34:18 <tl> q+
16:34:18 <gkellogg> ... I understand that we need expressive power and clean formalizations, but none of this matters if its too confusing.
16:34:45 <TallTed> *named graphs* are sets of *asserted* triples.
16:34:45 <TallTed> *reified* *triple_terms* are not asserted.
16:34:45 <TallTed> *reification statements* are asserted.
16:35:34 <gkellogg> enrico: People have made most of the arguments already, but ora said that a multi-reifier is confused with graph.
16:35:42 <TallTed> q+
16:36:00 <gkellogg> ... I don't see why it's that confusing, it's not naming a triple, but a triple term.
16:36:17 <gkellogg> ... It may be hard to use, but I don't see how restricting its usage makes things easier.
16:36:35 <gkellogg> ... There's not connection between a set of triples and a graph.
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16:37:09 <gkellogg> ... When I have something connected to multiple other things does not say it's connected to the set of those things.
16:37:17 <gkellogg> ... A graph is more than just a set of triples.
16:37:51 <pchampin> I agree with Enrico that "being related to N elements" is different from "being related to a set of N elements"
16:37:51 <gkellogg> ... A graph has the same bnode scope as the graph, but not between graphs.
16:38:15 <gkellogg> ora: I'm not saying its different, but it's going to be confused.
16:38:23 <pchampin> but I strongly disagree that an RDF graph is more than a set of triples; this is exactly how the spec defines an RDF graph
16:38:54 <gkellogg> enrico: the other argument is that if we want a unique restriction, you now need to be able to verify that it is unique.
16:39:15 <gkellogg> ... You would need to assume that the different triples are really the same.
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16:39:37 <gkellogg> ... This means that SPARQL with simple entailments should take that into account.
16:40:08 <gkellogg> ... You should always allow for arbitrary graphs, which is always possible under RDF semantics.
16:40:39 <niklasl> From last SemTF meeting: "All graphs are sets of triples, but not all sets of triples are graphs."
16:40:44 <gkellogg> ... If I have a standard RDF graph where some nodes are triple terms I don't see the problem?
16:41:04 <gkellogg> ... It's a problem if we need to restrict to just be a single reifier.
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16:41:34 <gkellogg> ... A refier could be anything, and the meaning of it could come from different perspectives.
16:41:36 <gkellogg> q?
16:41:42 <ora> ack tl
16:41:53 <TallTed> present+ Dominik_Tomaszuk
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16:42:30 <AndyS> present+
16:42:45 <gkellogg> tl: The seminal use case for RDF-star has been a prominent use case, and you can't know if it's an annotation of a single triple or multiple you can't really know.
16:43:33 <gkellogg> ... Things can get more complicated. One proposal was to rely on named graphs.
16:44:10 <gkellogg> ... Everything that needs semantics could be moved to the new space of triple and set-of-triple annotations.
16:44:28 <gkellogg> ... That would be a move away from named graphs for things that needs semantics.
16:45:54 <gkellogg> kurt: If you have a many relationship you're opening up the possibility that RDF is a hyper graph.
16:46:31 <gkellogg> ... I don't see a problem with that, but I think people suffer with the 1-1 relationship because they're trying to move into a set relationship. It's not just about reifications.
16:46:49 <ora> ack TallTed
16:47:14 <gkellogg> TallTed: The major difference between reification and named graphs is that triples in named graphs are asserted.
16:47:34 <tl> q?
16:47:38 <tl> q+
16:47:39 <gkellogg> ... Triple terms inside of reification statements (one or multiple) are unasserted and basically literals.
16:48:07 <gkellogg> ... Until you want to ask who said something, in which case they need to be broken out, but not in the merged graph space of many stores.
16:48:39 <gkellogg> ... Every triple term needs to be treated as its own singleton graph. Whether we have a single identifier for multiple statements or not.
16:48:40 <Souri> q+
16:49:00 <gkellogg> ... A collection of triple terms is outside of the graph space.
16:49:07 <ora> ack tl
16:49:19 <gkellogg> ... Implementing these things may be challenging, but not implausible.
16:49:32 <ora> ack Souri
16:49:39 <gkellogg> tl: It depends on your implementation if triples in named graphs are asserted.
16:49:39 <Souri> Aren't the concepts of Named Graph and Atomic Reification orthogonal? GRAPH :g { :e rdf:reifies <<( :s rdf:type :Married, :Single )>> } . Many-to-many rdf:reifies=> A (single) reifier for a set of (atomic) reifications VS. NamedGraph=>An identifier (graph name) for a set of asserted triples and reifications.
16:50:01 <gkellogg> Souri: We said we can't use named graphs for edge properties.
16:50:16 <gkellogg> ... Are the concepts of named graphs and atomic reification ...
16:50:41 <gkellogg> ... I could construct a named graph containing reified triples and say that it is a triple inside the graph.
16:50:52 <gkellogg> ... The two concepts complement each other.
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16:51:22 <gkellogg> ... I should be able to put a reification within a named graph.
16:51:35 <ora> q?
16:51:52 <gkellogg> ora: Good discussion.
16:52:04 <olaf> present+ Kurt
16:52:05 <gkellogg> ... My mind is less made up than it was before.
16:52:13 <gkellogg> ... We need to continue the discussion.
16:52:22 <pfps> I'm on the side of Ted in this discussion.
16:52:31 <gkellogg> ... I presume there is no semantics call tomorrow due to hollidays.
16:52:49 <gkellogg> ... I suggest we continue the discussion on the mailing list.
16:53:36 <gkellogg> ktk: It's time to vote on RDF Canonicalization for those who can, but April 23.
16:54:00 <ktk> s/but April/by April/
16:54:02 <gkellogg> topic: introctions
16:54:41 <gkellogg> Kurt: My name is Kurt Kagle, and have been following RDF for some time. Work on LinkedIn and elsewhere talks extensively about RDF.
16:54:49 <TallTed> present- kurt_cagle
16:54:49 <TallTed> present+ Kurt
16:54:56 <TallTed> RRSAgent, draft minutes
16:54:57 <RRSAgent> I have made the request to generate https://www.w3.org/2024/03/28-rdf-star-minutes.html TallTed
16:55:18 <gkellogg> ... I'm following the discussions with much interest. Whether or not it can be confused, I need to struggle with it.
16:55:23 <TallTed> s/introctions/introductions
16:55:42 <gkellogg> ... I have an audience of about 10,000 people I need to describe this to.
16:55:50 <TallTed> RRSAgent, draft minutes
16:55:52 <RRSAgent> I have made the request to generate https://www.w3.org/2024/03/28-rdf-star-minutes.html TallTed
16:56:12 <gkellogg> zakim, end meeting
16:56:12 <Zakim> As of this point the attendees have been TallTed, ktk, gkellogg, pfps, eBremer, gtw, ora, tl, pchampin, niklasl, olaf, Souri, Dominik_T, enrico, kurt_cagle, Dominik_Tomaszuk, AndyS
16:56:16 <Zakim> RRSAgent, please draft minutes
16:56:17 <RRSAgent> I have made the request to generate https://www.w3.org/2024/03/28-rdf-star-minutes.html Zakim
16:56:23 <Zakim> I am happy to have been of service, gkellogg; please remember to excuse RRSAgent.  Goodbye
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16:58:25 <TallTed> s/Whether we have a single identifier for multiple statements or not./If we have a single identifier for multiple triple_terms, then those triple_terms with the same identifier should be treated as one graph, solving the concerns of blank nodes, among other things.
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17:00:32 <TallTed> s/A collection of triple terms is outside of the graph space/A collection of triple terms must be treated as outside of the default graph space unless explicitly queried (by whatever mechanism we haven't quite defined)
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17:32:44 <TallTed> RRSAgent, bye
17:32:44 <RRSAgent> I see no action items
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17:32:56 <RRSAgent> logging to https://www.w3.org/2024/03/28-rdf-star-irc
17:33:01 <TallTed> RRSAgent, draft minutes
17:33:02 <RRSAgent> I have made the request to generate https://www.w3.org/2024/03/28-rdf-star-minutes.html TallTed
17:33:28 <TallTed> RRSAgent, bye
17:33:35 <TallTed> RRSAgent, make logs public
17:33:38 <TallTed> RRSAgent, bye
17:33:38 <RRSAgent> I see no action items
<gkellogg> s/Kagle/Cagle/g
<gkellogg> s/kurt_cagle/Kurt/
<gkellogg> s/Pix-NG/PICS-NG/
<gkellogg> s/RDF Canonicalization/RDF Dataset Canonicalization/