Re: Three ideas

Earlier I wrote:

> the temporal validity of any statement is implicitly lower-bounded by the
> existence of the things that it talks about


I wouldn't mind some feedback on this, but I think the temporal validity of
every statement has an implicit upper bound too:

Implicit lower bound: Existence of the things being described.
Implicit upper bound: Stated time of assertion, otherwise the present.

If that's correct, I can use it to demonstrate optional time and space
positions:

It's 2010, and Pierre-Antoine sends me a graph. He puts a timestamp on his
graph by upper-bounding the temporal validity:

{
    :BarackObama :presidentOf :UnitedStates 2009 _,
    :JoeBiden :vicePresidentOf :UnitedStates 2009 _,
    :HillaryClinton :secretaryOfStateOf :UnitedStates 2009 _,
}
    _ 2010

It's now 2022, and I'm working on my own graph:

{
    :JoeBiden :presidentOf :UnitedStates 2021 _,
    :KamalaHarris :vicePresidentOf :UnitedStates 2021 _,
    :AntonyBlinken :secretaryOfStateOf :UnitedStates 2021 _,
}

I trust Pierre-Antoine and remember that he sent me a graph a long time
ago. I do the laziest thing possible and import it unmodified as a compound
statement. The information is incomplete but the OWA means everything is
ok, and the graph is still valid:

{
    {
        :BarackObama :presidentOf :UnitedStates 2009 _,
        :JoeBiden :vicePresidentOf :UnitedStates 2009 _,
        :HillaryClinton :secretaryOfStateOf :UnitedStates 2009 _,
    }
        _ 2010,
    :JoeBiden :presidentOf :UnitedStates 2021 _,
    :KamalaHarris :vicePresidentOf :UnitedStates 2021 _,
    :AntonyBlinken :secretaryOfStateOf :UnitedStates 2021 _,
}

I do automated flattening of the graph. The information is incomplete, but
the graph is still valid:

{
    :BarackObama :presidentOf :UnitedStates 2009 2010,
    :JoeBiden :vicePresidentOf :UnitedStates 2009 2010,
    :HillaryClinton :secretaryOfStateOf :UnitedStates 2009 2010,
    :JoeBiden :presidentOf :UnitedStates 2021 _,
    :KamalaHarris :vicePresidentOf :UnitedStates 2021 _,
    :AntonyBlinken :secretaryOfStateOf :UnitedStates 2021 _,
}

I finally get the motivation and I update Pierre Antoine's statements. The
information is now up to date and the graph is still valid:

{
    :BarackObama :presidentOf :UnitedStates 2009 2017,
    :JoeBiden :vicePresidentOf :UnitedStates 2009 2017,
    :HillaryClinton :secretaryOfStateOf :UnitedStates 2009 2013,
    :JoeBiden :presidentOf :UnitedStates 2021 _,
    :KamalaHarris :vicePresidentOf :UnitedStates 2021 _,
    :AntonyBlinken :secretaryOfStateOf :UnitedStates 2021 _,
}

I decide to send it back to Pierre-Antoine, and I put a timestamp on my
graph:

{
    :BarackObama :presidentOf :UnitedStates 2009 2017,
    :JoeBiden :vicePresidentOf :UnitedStates 2009 2017,
    :HillaryClinton :secretaryOfStateOf :UnitedStates 2009 2013,
    :JoeBiden :presidentOf :UnitedStates 2021 _,
    :KamalaHarris :vicePresidentOf :UnitedStates 2021 _,
    :AntonyBlinken :secretaryOfStateOf :UnitedStates 2021 _,
}
    _ 2022

And so it could continue. Spatial validity would be handled similarly.

It's very easy to reason about temporal/spatial validity when the approach
to statements is unified and optional time and space positions can be used
everywhere.

Regards
Anthony

On Wed, Jan 12, 2022 at 12:48 PM Anthony Moretti <anthony.moretti@gmail.com>
wrote:

> Correction, I was a bit sloppy:
>
> In both cases I would leave the time and space positions blank anyway, so
>> RDF-as-usual.
>>
>
> In the second example the space position would be blank, but not the time
> positions. I was just trying to agree that yes the second example isn't
> place-dependent.
>
> Regards
> Anthony
>
> On Wed, Jan 12, 2022 at 12:44 PM Anthony Moretti <
> anthony.moretti@gmail.com> wrote:
>
>> Hi Pierre-Antoine
>>
>>> What is not entirely clear to me is how you see the ideas below interact
>>> with RDF-star —or RDF, for that matter...
>>>
>>> 1) Do you want to modify the core of RDF / RDF-star, replacing their
>>> notion of statement by the one you propose here (time+place annotated,
>>> complex and/or compound)?
>>>
>>> 2) Or do you want to explore how your proposed notion of statement could
>>> be expressed *on top* of RDF / RDF-star, with no or minimal modification to
>>> them?
>>>
>>> If the answer is 2 (my favorite option, by the way), then the idea is to
>>> model anthony-statements using a set of rdf-statements (possibly extended
>>> with RDF-star).
>>>
>>
>> Ideally:
>> RDF: Time and space positions.
>> RDF-Star: Simple, compound, and complex statements.
>>
>> It would be ideal to put the time and space positions at the RDF level
>> because, as Pat and Fabio seem to agree, some triples are time/space
>> dependent and make no sense without that information. They're not edge
>> cases either, it might seem like that because so far there hasn't been a
>> way to express them, but there are infinitely many just as there are
>> infinitely many that aren't time/space constrained. Also, the order of
>> assertion is important for time/space dependent triples, if anything is to
>> be said about them, additional data or metadata, then the time/space
>> constraints need to be asserted first, and time and space positions ensure
>> that order of assertion.
>>
>> I think it would help the discussion a lot to a) acknowledge that the
>>> word "statement" in this discussion is ambiguous, and b) to be as explicit
>>> as possible about which kind we are talking about.
>>>
>>
>> I'm using the word "statement" as a direct replacement for "sentence", so
>> maybe "sentence" is a better term:
>>
>> sentence:
>> *a set of words that is complete in itself, typically containing a
>> subject and predicate, conveying a statement, question, exclamation, or
>> command, and consisting of a main clause and sometimes one or more
>> subordinate clauses.*
>>
>> I am uncomfortable with "hard-coding" these 4 dimensions, and only them,
>>> in every possible statement. I think that the relevant dimensions depend on
>>> the relation itself (e.g., the birth-date of a person is neither time nor
>>> place dependent; the president of a country is not place dependent...). And
>>> I don't think that any list of contextual dimension can be exhaustive.
>>>
>>> Especially regarding certainty, there are many ways to model uncertainty
>>> (not all of them modelling it with a single value between 0 and 1, by the
>>> way).
>>>
>>
>> On the first example you gave, my thoughts are that the temporal validity
>> of any statement is implicitly lower-bounded by the existence of the things
>> that it talks about, so technically the birth-date example is only valid
>> after the birth date of the person, the birth date happens to be the object
>> of the statement in this case but the idea would apply to any statement. On
>> the second example, yes I agree its spatial validity is unbound. In both
>> cases I would leave the time and space positions blank anyway, so
>> RDF-as-usual.
>>
>> I'm happy to drop "certainty" for the reasons you stated. I've included
>> it so far because it's another example of where order of assertion becomes
>> important, for it to make sense it needs to be asserted after time and
>> space but before metadata. But yes, let's drop it for now.
>>
>> And yes for sure, no list of contextual dimensions can be exhaustive, but
>> if time and space positions are allowed it ensures those assertions are
>> made first and the whole framework becomes scalable and easier to reason
>> about.
>>
>> Do you have any clear definition, or at least guidelines, to decide
>>> whether a piece of information is additional data or metadata?
>>>
>>
>> My quick take would be: additional data continues the description,
>> whereas metadata is description of the description.
>>
>> No widespread need, but logically it could continue, descriptions of
>> descriptions of descriptions and so on:
>>
>> Simple statement
>>     { Additional data }
>>     {| First-order metadata |}
>>     {| Second-order metadata |}
>>     ...
>>
>> Fabio has a good idea with the note containing examples of good modeling.
>>
>> Regards
>> Anthony
>>
>> On Wed, Jan 12, 2022 at 8:02 AM Fabio Vitali <fabio.vitali@unibo.it>
>> wrote:
>>
>>> Dear Pierre-Antoine,
>>>
>>> > 1) Do you want to modify the core of RDF / RDF-star, replacing their
>>> notion of statement by the one you propose here (time+place annotated,
>>> complex and/or compound)?
>>>
>>>
>>> I think with you that RDFstar already provides a lot of what has been
>>> discussed so far.
>>>
>>> Yet Anthony explicitly mentions (and I agree with him) that RDFstar has
>>> the right approach for single triples, but is lacking in supporting the
>>> needs for complex and compound statements. Working towards some suggestions
>>> to integrate these needs would enrich and complete the RDFstar proposal.
>>>
>>> My preference would go towards exploiting named graphs, explicitly
>>> introducing unasserted named graphs that can then be used in RDFstar in the
>>> same way of unasserted triples.
>>>
>>> > 2) Or do you want to explore how your proposed notion of statement
>>> could be expressed *on top* of RDF / RDF-star, with no or minimal
>>> modification to them?
>>>
>>> I do not know Anthony's point of view on this, but I believe that it
>>> would be useful to think of a resource providing some thoughtful and
>>> general guidelines on how RDFstar's quoted and annotated triples (as well
>>> as, hopefully, the RDFstar's quoted and annotated named graphs that I
>>> envision) could help in expressing conditional, time-dependent,
>>> location-dependent, uncertain, opinionated and competing statements.
>>>
>>> What I am thinking is something like, say, a W3C note, on the lines of
>>> https://www.w3.org/TR/swbp-n-aryRelations/ : a document introducing no
>>> new features, but explaining and making examples on how to use the existing
>>> features in a possibly unexpected and innovative way.
>>>
>>> What do you think?
>>>
>>> Fabio
>>>
>>> --
>>>
>>> > On 11 Jan 2022, at 15:43, Pierre-Antoine Champin <
>>> pierre-antoine.champin@ercim.eu> wrote:
>>> >
>>> > Hi Anthony,
>>> >
>>> > thanks for the summary. It's hard to catch up for those of us who went
>>> offline during the break :-)
>>> >
>>> > On 08/01/2022 10:40, Anthony Moretti wrote:
>>> >> Hi
>>> >>
>>> >> I thought I'd put the ideas I shared during the longer discussion in
>>> one place to make it easier for people to read and give feedback. I love
>>> what's been achieved so far, I just want whatever is released to be the
>>> best possible thing that could be released.
>>> > What is not entirely clear to me is how you see the ideas below
>>> interact with RDF-star —or RDF, for that matter...
>>> >
>>> > 1) Do you want to modify the core of RDF / RDF-star, replacing their
>>> notion of statement by the one you propose here (time+place annotated,
>>> complex and/or compound)?
>>> >
>>> > 2) Or do you want to explore how your proposed notion of statement
>>> could be expressed *on top* of RDF / RDF-star, with no or minimal
>>> modification to them?
>>> >
>>> > If the answer is 2 (my favorite option, by the way), then the idea is
>>> to model anthony-statements using a set of rdf-statements (possibly
>>> extended with RDF-star). I think it would help the discussion a lot to a)
>>> acknowledge that the word "statement" in this discussion is ambiguous, and
>>> b) to be as explicit as possible about which kind we are talking about.
>>> >
>>> > I also have a few comments on the two first ideas:
>>> >
>>> >> (...)
>>> >>
>>> >> Summary:
>>> >> 1. Optional time, space, and certainty positions.
>>> > I am uncomfortable with "hard-coding" these 4 dimensions, and only
>>> them, in every possible statement. I think that the relevant dimensions
>>> depend on the relation itself (e.g., the birth-date of a person is neither
>>> time nor place dependent; the president of a country is not place
>>> dependent...). And I don't think that any list of contextual dimension can
>>> be exhaustive.
>>> >
>>> > Especially regarding certainty, there are many ways to model
>>> uncertainty (not all of them modelling it with a single value between 0 and
>>> 1, by the way). On that particular topic, you might be interested in this
>>> paper:
>>> https://hal.inria.fr/hal-02167174/file/Publishing_Uncertainty_on_the_Semantic_Web__Bursting_the_LOD_bubbles__Final_Version_.pdf
>>> >
>>> >> 2. Separating additional data from metadata.
>>> > Do you have any clear definition, or at least guidelines, to decide
>>> whether a piece of information is additional data or metadata?
>>> >
>>> >   best
>>> >
>>> >> 3. Simple, compound, and complex statements.
>>> >> - - -
>>> >>
>>> >> 1. Optional time, space, and certainty positions
>>> >>
>>> >> We exist in time and space, and this type of modeling could possibly
>>> be easier. A statement would have four optional positions, leaving the time
>>> and space positions blank would mean "unbounded", and leaving the last
>>> position blank would mean 1.0:
>>> >>
>>> >> Subject Relation Object T1 T2 SpatialBound Certainty
>>> >>
>>> >> Examples:
>>> >>
>>> >> :RichardB :marriedTo :LizT 1964 1974
>>> >> :RichardB :marriedTo :LizT 1975 1976
>>> >>
>>> >> :BigMac :price-USD 7.30 T1 T2 :Switzerland
>>> >> :BigMac :price-USD 1.62 T1 T2 :India
>>> >>
>>> >> If anybody has worked with temporal databases they might see an
>>> analogy with "valid times". By extension, the spatial bound could be
>>> thought of as a "valid place".
>>> >>
>>> >> 2. Separating additional data from metadata
>>> >>
>>> >> This would remove a lot of ambiguity and creates a clear order of
>>> assertion. It also seems to match the Wikidata data model.
>>> >>
>>> >> Example:
>>> >>
>>> >> :LizT :starredIn :JaneEyre
>>> >>     {
>>> >>         :role :HelenBurns,
>>> >>         :pay-USD 10000,
>>> >>     }
>>> >>     {|
>>> >>         :statedBy :Bob,
>>> >>         :statedIn :Wikipedia,
>>> >>     |}
>>> >>
>>> >> 3. Simple, compound, and complex statements
>>> >>
>>> >> Taking inspiration from linguistics, there could be four different
>>> types of statements:
>>> >>
>>> >> 1. Simple statement
>>> >> 2. Compound statement
>>> >> 3. Complex statement
>>> >> 4. Compound-complex statement
>>> >>
>>> >> Simple statement (binary relationship):
>>> >> S R O T1 T2 SB C
>>> >>
>>> >> Compound statement (graph):
>>> >> {
>>> >>     S R O T1 T2 SB C,
>>> >>     S R O T1 T2 SB C,
>>> >>     S R O T1 T2 SB C,
>>> >> }
>>> >>     T1 T2 SB C
>>> >>
>>> >> Complex statement (n-ary relationship):
>>> >> S R O T1 T2 SB C
>>> >>     {
>>> >>         R O T1 T2 SB C,
>>> >>         R O T1 T2 SB C,
>>> >>     }
>>> >>
>>> >> Compound-complex statement (n-ary relationship):
>>> >> {
>>> >>     S R O T1 T2 SB C,
>>> >>     S R O T1 T2 SB C,
>>> >>     S R O T1 T2 SB C,
>>> >> }
>>> >>     T1 T2 SB C
>>> >>     {
>>> >>         R O T1 T2 SB C,
>>> >>         R O T1 T2 SB C,
>>> >>     }
>>> >>
>>> >> This creates consistency, and makes it easy to reason about the
>>> temporal/spatial validity of any graph.
>>> >>
>>> >> The existing RDF-Star "<<" and ">>" delimiters could be applied to
>>> statements of any type to say that a statement was "neutrally asserted", as
>>> I think Pat has described it before. Maybe for completeness, and based on
>>> something Pat published, other delimiters could be created that would mean
>>> "negatively asserted", something like "<!" and "!>" for example.
>>> >>
>>> >> The existing RDF-Star "{|" and "|}" delimiters could be applied to
>>> statements of any type to add metadata. The example in Section 2 of this
>>> email is an example of a complex statement with metadata.
>>> >>
>>> >> And I'm not sure, but it seems that nesting statements could be a
>>> general solution to contexts, the deepest nested statements would be in the
>>> most specific contexts. I haven't examined it properly though.
>>> >>
>>> >> If you've made it here thanks for reading! If you need more examples
>>> please ask and I'll do my best. I love everything done so far, I just want
>>> to bounce around these additional ideas with the hope that they're
>>> constructive. Please reply with any feedback at all, good and bad, it's all
>>> welcome!
>>> >>
>>> >> Regards
>>> >> Anthony
>>> > <OpenPGP_0x9D1EDAEEEF98D438.asc>
>>>
>>>