Re: RDF* vs RDF vs named graphs

It's not just that the examples don't reflect the best way to address their
use cases.  It's that the examples are inadequate to express what appears to
be their use cases.  Either the examples need to be changed, the use cases
need to be changed, or RDF* needs to be changed.


peter



On 12/4/20 4:38 AM, Pierre-Antoine Champin wrote:
> Perer,
>
>> What should be concluded from this?  Just about the most charitable conclusion
>> is that RDF* is unsuitable for its claimed use.
>
> the fact that the examples do not reflect the best way to address their
> use-cases using RDF* (as it is formally defined) does not mean that such a
> way does not exist.
>
> Don't get me wrong: I am not trying to minimize the fact that such examples
> are, in a way, harmful. Clearly, they have created a lot of
> misunderstanding. One could even think that the popularity of RDF* happened
> for bad reasons, because people saw in those example something that was not
> here (in the formal definition, nor in the implementations).
>
> What makes me more optimistic is, precisely, that we have implementations,
> some of them deployed in commercial products. I'll leave the implementers
> comment on that, but I'm curious to know how their customers are using RDF*,
> and whether the unicity of embedded triples raised that many problems.
>
> Just a small comment below on one of the examples that you quote:
>
> On 03/12/2020 00:47, Peter F. Patel-Schneider wrote:
>> I certainly agree with Thomas that examples used throughout the RDF* documents
>> and discussions are ill-supported by the various formal definitions underlying
>> RDF*.
>>
>> We see
>>
>> :bob foaf:name "Bob" .
>> <<:bob foaf:age 23>>
>>    dct:creator <http://example.com/crawlers#c1> ;
>>    dct:source <http://example.net/listing.html> .
>>
>> in http://ceur-ws.org/Vol-1912/paper12.pdf
>>
>> <<:painting :height 32.1>>
>>    :unit :cm;
>>    :measurementTechnique :laserScanning;
>>    :measuredOn "2020-02-11"^^xsd:date.
>>
>> <<:man :hasSpouse :woman>>
>>    :source :TheNationalEnquirer;
>>    :webpage <http://nationalenquirer.com/news/2020-02-12>;
>>    :retrieved "2020-02-13"^^xsd:dateTime.
>>
>> in
>> https://graphdb.ontotext.com/documentation/9.2/free/devhub/rdf-sparql-star.html
>>
>> <<:Bess_Schrader :employedBy :Enterprise_Knowledge . >> :dateAdded
>> "2020-05-22" .
>> <<:Bess_Schrader :employedBy :Enterprise_Knowledge . >> :addedBy
>> :user_bscrader .
>>
>> in https://enterprise-knowledge.com/rdf-what-is-it-and-why-do-i-need-it/
>
> I can't help but notice that the embedded triple is repeated here, although
> the intention is clearly to put two annotations on the same arc -- the
> illustrating figure leaves no doubt about that:
>
> https://enterprise-knowledge.com/cms/assets/uploads/2020/07/rdf_7.jpeg
>
> so that person does not seem to assume that multiple embedded triples
> represent different arcs...
>
>     best
>
>>
>> <<?c a rdfs:Class>> dct:source ?src ;
>>      prov:wasDerivedFrom <<?c a owl:Class>> .
>>
>> :loisLane :believes << :superman :can :fly >>.
>>
>> in https://w3c.github.io/rdf-star/rdf-star-cg-spec.html
>>
>>
>>
>> What should be concluded from this?  Just about the most charitable conclusion
>> is that RDF* is unsuitable for its claimed use.
>>
>> So what is RDF* good for?  I am concerned about this.
>>
>>
>> peter
>>
>>
>>
>>
>

Received on Friday, 4 December 2020 16:06:56 UTC