Re: [External] : Re: use of multi-valued rdf:reifies removes ability to annotate individual triple-patterns

[There was a copy/paste typo in my example: It should have had => :f2 rdf:reifies <<( :s3 :p3 :o3 )>> .]

Hi Peter,

Yes, because your example too involves a multi-valued property, if we think of the inverse property :sourceOf.

So, my point is that, as shown in my examples, using rdf:reifies in a multi-valued manner may lead to the need to change the data significantly (if the need for annotation of individual triple-terms arises later). That would involve query rewriting as well. So, modeling using multi-valued rdf:reifies could a bit risky.

Thanks,
Souri.

________________________________
From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
Sent: Sunday, April 14, 2024 5:17 PM
To: public-rdf-star-wg@w3.org <public-rdf-star-wg@w3.org>
Subject: [External] : Re: use of multi-valued rdf:reifies removes ability to annotate individual triple-patterns

This modelling issue is not specific to :reifies.

Consider

:a :source :x .
:b :source :x .
:x :publication "NYT" .

This says that :a and :b have the same :source, whatever that means.  If you
later want to add more information about :source, for example :year, then you
can't put different :years for this :source.   You have to either have the
same :year or make a change to something like:

:a :source :x .
:b :source :y .
:x :publication "NYT" .
:x :year 2023 .
:y :publication "NYT" .
:y :year 2022.

This says that :a and :b have the same value for the :date.

peter


On 4/14/24 14:37, Souripriya Das wrote:
> A shortcoming of using multi-valued rdf:reifies is that you lose the ability
> to add statements about the individual triple-terms. I have tried illustrating
> this with the following simple examples.
>
> Example 1: using multi-valued rdf:reifies
> =========
> :e rdf:reifies <<( :s1 :p1 :o1 )>>, <<( :s2 :p2 :o2 )>> ; :source :src1 ;
> :year 2023 .
> :f rdf:reifies <<( :s1 :p1 :o1 )>>, <<( :s3 :p3 :o3 )>> ; :source :src2 ;
> :year 2024 .
>
> What if we want to indicate that the <<(: s1 :p1 :o1 )>> triple-term in :e has
> a different :month annotation than the one in :f? The following does not help
> because we cannot specify that the one in :e is associated with :g and the one
> in :f is associated with :h.
>
> :g rdf:reifies <<( :s1 :p1 :o1 )>> ; :month 5 .
> :h rdf:reifies <<( :s1 :p1 :o1 )>> ; :month  12 .
>
> Example 2: using single-valued rdf:reifies, along with rdfs:member (or some
> similar) property
> =========
>
> :e1 rdf:reifies <<( :s1 :p1 :o1 )>> .
> :e2 rdf:reifies <<( :s2 :p2 :o2 )>> .
> :e rdfs:member :e1, :e2 ; :source :src1 ; :year 2023 .
>
> :f1 rdf:reifies <<( :s1 :p1 :o1 )>> .
> :f2 rdf:reifies <<( :s2 :p2 :o2 )>> .
> :f rdfs:member :f1, :f2 ; :source :src2 ; :year 2024 .
>
> This is a multi-level structure that, although more verbose, allows
> annotations at each level. So, the following achieves the objective.
>
> :e1 :month 5 .
> :f1 :month 12 .
>
> The second approach – using single-valued rdf:reifies and rdfs:member –
>   allows one to use a uniform way to create multi-level structures (e.g., a
> document with levels: chapter -> section-> paragraph -> sentence).
>
> Thanks,
> Souri.
>
>
>
>