Re: Blog post about "Provenance in RDF-star"

dear Antoine, 

> On 27 Jan 2022, at 10:30, Antoine Zimmermann <antoine.zimmermann@emse.fr> wrote:
> 
> Pierre-Antoine,
> 
> 
> I think the description of the intended meaning of the RDF-star graphs given in this post are not aligned with the formal meaning given in the spec. Or, at least, that the presentation is misleading the reader into misusing quoted triples for provenance (or for anything, for that matter).
> 
> Bare with me for a moment, as I have to place my arguments one at a time before concluding.
> 
> You give this example:
> 
> """
> PREFIX : <http://www.example.org/>
> 
> :employee38 :familyName "Smith" .
> << :employee38 :jobTitle "Assistant Designer" >> :accordingTo :employee22 .
> """
> 
> and say: "The intended meaning of this small RDF-star graph is: “employee #38 is named Smith, and employee #22 claims that employee #38 is an assistant designer”."

is there something more complicated hidden in your words, or would your objection be satisfied by expressing the natural language explanation as: "The intended meaning of this small RDF-star graph is: “employee #38 is named Smith, and employee #22 claims that employee #38 is an assistant designer”, ** assuming these were the respective intended meanings for properties :familyName, :jobTitle, and :accordingTo.**  "?

Thanks for any light you may shed on this.

Fabio

--

> 
> The problem here is that a reader may conclude that, if they want to say “employee #38 is named Smith, and employee #22 claims that employee #38 is an assistant designer”, among other things, they can just take your example and integrate it in their data set. This may not be sensible, depending on what they want to say about the claim, and most importantly, what they *don't* want to say about it.
> 
> The issue is that, by saying "The intended meaning of this RDF-star graph is [explanation]", you actually want to say "As part of the intended meaning of this RDF-star graph, we have that [explanation]". But this is not the full meaning of the RDF-star graph. Indeed, due to the RDF-star semantics, there is additional meaning imposed by the spec itself.
> 
> The spec says that this RDF-star graph also carries the meaning that the claim is related to the URIs ":employee38" and ":jobTitle" in a specific way, and related to the string literal """"Assistant Designer"^xsd:string""". If one merely wants to say that "employee 22 claims that employee 38 is an assistant designer", one perhaps *does not* want to relate this claim to the URI ":jobTitle".
> 
> When you define the intended meaning, you can say whatever you like about what the URIs denote, as long as they are not among the standard URIs of the spec. So you can say, for instance, that ":accordingTo" denotes the relation that exists between a claim and the people who make the claim. But you cannot define the intended meaning of a structure of the language, like quoted triples, which is defined by the spec.
> 
> As an analogous example, consider standard RDF and the following RDF-graph:
> 
> """
> :claim1 :accordingTo "Pierre-Antoine".
> """
> 
> You can say that ":accordingTo" is intended to mean the relation between a claim and a person, but you cannot say that the intended meaning of this triple is that ":claim1" is claimed by a person named "Pierre-Antoine". Given the intention that ":accordingTo" relates a claim to a person, this graph is implying that the character string "Pierre-Antoine" is a person, which is absurd.[*]
> 
> With such examples and explanations in your post, you are suggesting the audience that they can use your RDF-star examples as templates for the intended meanings you present. So you are telling the audience that they can use RDF-star graphs in ways that clash with the formal semantics. In other words, you are openly showing that the RDF-star semantics can be safely ignored.
> 
> As a consequence, I do not see how there could be, and why there should be, any support for the current formal semantics of the spec. Either throw it to the bin (allowing anyone to form their own interpretations of what quoted triples entail) or revise it such that it matches the intended meanings suggested by its authors.
> 
> 
> 
> [*] of course, one could interpret ":accordingTo" as: "the relation between a claim and the first name of a person that makes the claim". Similarly, one could interpret ":accordingTo" as "the relation between a claim that's attached to certain terms in subject, predicate, and object positions, and a person who makes a claim with these terms". But presenting the blog post in this way would ruin the attractiveness of RDF-star very much.
> 
> 
> 
> Best,
> --AZ
> 
> 
> 
> 
> 
> Le 26/01/2022 à 21:34, Pierre-Antoine Champin a écrit :
>> Dear all,
>> following a discussion during our two last calls, I published a post about "Provenance in RDF-star":
>> https://www.w3.org/community/rdf-dev/2022/01/26/provenance-in-rdf-star/

>> quoting the intro:
>> > In this post, we present some lessons learned by the group through discussions and exchanges. This is meant to give some insight about the rationale behind RDF-star, and some guidelines about how to best use it for modeling provenance data.
>> Many thanks to all the participants of the RDF-star group for their reviews and feedback on this post.
>>   pa
> 
> 
> -- 
> Antoine Zimmermann
> ISI - Institut Henri Fayol
> École des Mines de Saint-Étienne
> 158 cours Fauriel
> 42023 Saint-Étienne Cedex 2
> France
> Tél:+33(0)4 77 42 66 03
> https://www.emse.fr/~zimmermann/

>

Received on Thursday, 27 January 2022 10:53:06 UTC