Re: SKOS transitive hierarchical relations

Hi Antoine!

Thanks for clarifying this! I found thesauri defining concepts related 
only with skos:broaderTransitive (and not with skos:broader) in the SKOS 
output of some proprietary thesaurus management tool. Also, I could spot 
some resources (like http://umbel.org/umbel/rc/Delicacy.rdf and 
http://lod.geospecies.org/ses/lEGJh?format=rdf) that only assert 
transitive hierarchical relations.
This might just be "outdated" or incomplete datasets, nevertheless they 
brought up the question. I think I will need to search for more examples 
in other publicly available vocabularies.

Christian

On 01/04/2012 03:26 PM, Antoine Isaac wrote:
> Hi Christian,
>
>
>>
>> Based on the discussions on this mailing list and the SKOS
>> reference/model documentation, my understanding of the
>> broader/narrower properties is that it is up to the application
>> (processing a SKOS vocabulary) to interpret the hierarchical
>> properties skos:broader and skos:narrower as transitive or not. Thus I
>> can understand why "By convention, skos:broaderTransitive is not used
>> to make assertions" (from the SKOS ontology).
>> However, there are vocabularies published on the Web that relate their
>> concepts using only skos:broaderTransitive (and not skos:broader).
>> Although these are valid statements, I wonder if, for interoperability
>> reasons, these vocabularies should additionally include skos:broader
>> relations alongside with the already contained skos:broaderTransitive
>> relations.
>> This way, e.g., SPARQL queries involving SKOS vocabularies of
>> different origin, might return a more complete result set if relying
>> on the convention mentioned above and only query for skos:broader.
>> Would it be, in your opinion, a useful feature for a thesaurus
>> management software to detect concepts that are only related by
>> skos:broaderTransitive and notify the user whether to automatically
>> add the skos:broader relation?
>
>
> In fact having thesauri published with only skos:broaderTransitive (and
> not skos:broader) is quite bad practice. Where have you seen this?
>
> Indeed, the original idea is that the vocabulary providers would start
> publish assertions with skos:broader/narrower.
> Then broader/narrowerTransitive statements could be infered, and
> materialized either by the thesaurus publisher or by a data consumer.
> Note that there is no real interpretation freedom here. The transitive
> properties are defined as super-properties of the unspecified ones. This
> means that everytime you have a skos:broader statement between two
> concepts, the semantics of SKOS imply that there is a
> skos:broaderTransitive statement holding as well.
> There is some more detail on this kind of inference at
> http://www.w3.org/TR/skos-primer/#sectransitivebroader.
>
> I hope this helps,
>
> Antoine
>
>

-- 
Research Group Multimedia Information Systems
Faculty of Computer Science
University of Vienna

Received on Wednesday, 4 January 2012 16:25:08 UTC