Re: [SKOS] proposed resolution for Issue 4 - BroaderNarrowerSemantics


First, just to ward off any ambiguity: I support Guus' resolution

Second: just a bit of explanation why I wanted in the post-telecon 
discussion to defend the transitiveBroader as a subproperty and not as a 
super-property, in spite of what is in the part-of pattern of [1]
(I'll let you decide whether this nail is a matter of scientific 
interest or personal pride. But I had never misunderstood the pattern of 
[1] ;-)

The point is that there is two possibilities for this transitivity effect:
1. It is controlled by the one who publishes the data:
If transitiveBroader as a subproperty of broader, then it amounts for 
the one who uses it just creates a KOS that includes all the broader 
links that can be inferred from the hierarchy. Even if the consumer of 
the data can still retrieve the "direct" broader by some procedure, this 
is a situation where the consumer is strongly encouraged to adhere to 
the point of view the publisher adopts on the transitivity of "his" 
broader statements.

2. It is controlled by the one who consumes the data:
If transitiveBroader as a superproperty of broader, then the publisher 
has a more neutral stance with respect to the way the hierarchy will be 
accessed. The consumer can decide whether he wants to get the transitive 
closure or the direct broader, by querying for the corresponding statements.

So the decision we are making here in favor of 1 is not neutral. But I 
won't argue against it, as it now seems to me to have strong application 
(and the publisher really motivated for option 1 can still create his 
own transitive specialization of skos:broader...)



> All,
> Based on the post-telecon discussion of today, I'm proposing the 
> resolution below.
> Guus
> Proposed RESOLUTION for Issue-44 BroiaderNarrowerSemantics
> 1. Given that:
> - in the thesaurus world BT (BroaderTerm) is used to assert a concept
> as the *direct* parent in of another concept in a BT/NT hierarchy, and
> - we prefer the skos:broader to resemble as closely as possible the
> intended meaning and/or accepted practice of using BT
> we RESOLVE that skos:broader is *not* a transitive property.
> 2. Given that:
> - in the thesaurus world there is  clear need to be able to talk about
> the transitive closure of the BT relation, and
> - it would be confusing if SKOS (given its RDF/OWL baseline) would
> *not* predefine such a transitive interpretation of BT, and
> - for reasons of logical consistency (see note below) a transitive 
> version of BT
> necessarily needs to be defined as a *superproperty* of its
> direct-parent variant
> we RESOLVE that the property skos:broaderTransitive is added to the
> SKOS vocabulary, and that this new property is defined as a
> owl:Transitive property and as a superproperty of skos:broader.
> 3. Identical resolutions hold for the inverse properties skos:narrower
> and skos:narrowerTransitive.
> NOTE: The extension of a transitive variant B of a property A always
> contains the same or more instances than the extension of property A.
> Therefore, B cannot be defined as a subproperty of A (unless A and B
> are the same, which is not what we intend when introducing B).  So,
> transitivity is *not* automatically inherited over the subproperty
> relationship. For a description of a similar modeling pattern, see
> the SWBPD note on representing simple part-whole relations [1].
> [1] 

Received on Tuesday, 15 January 2008 21:00:26 UTC