Abstract of Paper

An Abduction-based Method for Index Relaxation in Taxonomy-based Sources
by Carlo Meghini, Yannis Tzitzikas and Nicolas Spyratos


Indexing accuracy and consistency are difficult to maintain. Imposing a
standard indexing language (like the terminology of a taxonomy) tends to
improve consistency, but it does not improve accuracy. As a consequence, the
extraction of information from a source containing term-classified objects
is plagued with uncertainty. Commonly, this uncertainty is dealt with in a
quantitative way, by means of numerical methods. In the present paper we
deal with uncertainty in a qualitative way. We view an information source as
an agent, operating according to an open world philosophy. The agent knows
some facts, but is aware that there could be other facts, compatible with
the known ones, that might hold as well, although they are not captured for
lack of knowledge. These facts are, indeed, possibilities. Here we view
possibilities as explanations of knowledge facts and resort to abduction in
order to define precisely the possibilities that we want our system to be
able to handle. In particular, we introduce an operation that extends a
taxonomy-based source with possibilities, and then study the property of
this operation from a mathematical point of view.