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Erroneous use of skos:broaderTransitive in RDF file? #296

Open aisaac opened 6 years ago

aisaac commented 6 years ago

There is one thing that puzzles me is that the hierarchical relationships are represented as skos:broaderTransitive in the ontology at https://www.w3.org/ns/odrl/2/ODRL22.rdf it should have been skos:broader, following the pattern at https://www.w3.org/TR/skos-primer/#sectransitivebroader

I can probably live with this. but considering that it is a small change, that you may present it as fixing a typo, and that the ontology files are not in the TR space (and that the use of broaderTransitive seems to be nowhere explicit in the TR/ document) I thought I would flag it. And flag it only to you: I think it's fair to let you judge what is the best way to handle this - or not.

riannella commented 4 years ago

@vroddon @simonstey @nitmws Do you have any views on this?

simonstey commented 4 years ago

IIRC, we adopted the use of SKOS as it was done by the CG prior to the WG.. I reckon the confusion/misunderstanding(?) stems from the fact that the SKOS primer @aisaac referenced explicitly says:

As described in Section 2.3.1, the properties used to represent KOS hierarchies, skos:broader and skos:narrower, are not defined as transitive. As shown in Fig. 4.5.1 (i) & (ii), this means that their semantics do not support inferences of the type: if "animals" is broader than "mammals" and "mammals" is broader than "cats", then "animals" is broader than "cats". ... For the applications that require such semantics—for instance to perform query expansion—SKOS features two specific properties, skos:broaderTransitive and skos:narrowerTransitive. These are defined as transitive super-properties of skos:broader and skos:narrower [SKOS-REFERENCE]. This pattern enables, using a Semantic Web inferencing tool, access to the "transitive closure" of a hierarchy expressed with skos:broader and skos:narrower.

if skos:broaderTransitive and skos:narrowerTransitive are not meant to be declared directly but only inferred according to their non-transitive counterpart, I'm fine with replacing them 😃 (I'm no SKOS expert though)

aisaac commented 4 years ago

@simonstey I can confirm that replacing them would be the most appropriate option, following the SKOS practice :-)

riannella commented 2 months ago

Sorry for such a late response...

Is it an "error" that we use transitiveBroader/Narrow for a few properties?

Semantically it makes sense right?

It is not that useful as there are only 2 concepts in the hierarchy.

aisaac commented 2 months ago

Hi @riannella I still think replacing them would be much better. From a semantic perspective, you would actually lose an important part of the semantics, and it is actually less interoperable, as I expect very few will expect the "transitive" properties to be used here, and have measures to "understand" them.