RE : RE : aboutness and broader

Leonard, Simon,

> >
> >
> > True, which is why the document should be indexed with the most specific
> > term.
> >
> > [...]. The search system should be able to distinguish between searches for
> > items indexed with the term "animals" and searches for items indexed by the
> > term "animals" or any of its narrower terms. This is a function of the
> > search system, though, and does not require any special provision in the
> > thesaurus structure.

To add to a previous mail of Leonard, I don't think we disagree on what the 'real' indexing link should be for the document.
My problem is that if you add the axiom Alistair proposes, then a knowledge base that has both SKOS information and dc:subject would return, in a set of indistinguishable results, both the dc:subject 'at the right level' and the more general subjects that can be inferred from it.
Or more precisely: you can make the distinction, but then your query to the knowledge base should be different, more explicit, like 'find all the subjects of the book for which there is no specialization which is also a subject of a book'.

It could be perfectly valid from your point of view, but I rather see a search system activate itself some useful semantics (by explicitly asking for all the books indexed by a subject and all its descendants, which would give animals and platypus and so on)
rather than having it eventually to "de-activate" some semantics which were assumed as a default, and therefore did not apply to all cases (e.g. for a query like "I just want to display/access the subjects of this book as they were defined by a professional indexer")

> >
> > The indexing term "animals" would be assigned to documents which either
> >
> > a. Deal with animals in general
> > b. Deal with several types of animal, too many to index individually
> > c. Deal with a type of animal for which no more specific term exists in the
> > thesaurus.
>
>
> The only requirement placed on the syndetic  structure is support for
>  hierarchical relationships between terms such that  the narrower term is a
> proper subset of the broader one;  otherwise upward posting  and the rule of
> three (for suitable values of three)  don't work, and the use of specific
> terms will cause recall to drop.  Unfortunately, SKOS as it now stands
> doesn't support this kind of relationship.

Well maybe I don't understand your comment, but it seems to me that skos:broaderTransitive would allow for getting results without the recall drop.

Cheers,

Antoine