document.131

It is quite well established in recent
investigation on Information Systems, that


50 Int’l Journal on Semantic Web & Information Systems, 1(2), 48-68, April-June 2005
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formal ontologies are a crucial problem to
deal with, and, in fact, they received a lot
of attention in several different communities (e.g., knowledge management, knowledge engineering, natural language processing, intelligent information integration,
etc.) (Fensel, 2000). Ontologies have
been developed in Artificial Intelligence to
facilitate knowledge sharing and reuse, and
now are applied and intended to be used
in expert systems of almost all types of
industries. The concept of ontology that is
adopted in this chapter is taken from the
general considerations on the use of philosophical issues in Artificial Intelligence:
“the systematic, formal, axiomatic
development of the logic of all forms and
modes of being.”
(Cocchiarella, 1991, p.
000)
Another commonly accepted definition is that an ontology is an explicit
specification of a shared conceptualization
that holds in a particular context. The actual topic of ontology is one of those
themes that epistemology dealt with in
philosophical studies of Parmenides,
Heraclitus, Plato, Aristotle, Kant, Leibnitz,
Wittgenstein, and others. Ontologies define the kind of things that exist in the world
and, possibly, in an application domain.
In other words, an ontology provides an
explicit conceptualization that describes
semantics of data, providing a shared and
common understanding of a domain. From
an AI perspective we can say that:
“... ontology is a formal explicit
specification of a shared
conceptualization. Conceptualization
refers to an abstract model of
phenomena in the world by having
identified the relevant concepts of those
phenomena. Explicit means that the type
of concepts used, and the constraints on
their use are explicitly defined. Formal
refers to the fact that the ontology should
be machine readable. Shared reflect that
ontology should capture consensual
knowledge accepted by the
communities.”
(Gruber, 1993, p. 000 )
“... an ontology may take a variety of
forms, but necessarily it will include a
vocabulary of terms, and some
specification of their meaning. This
includes definition and an indication of
how concepts are inter-related which
collectively impose a structure on the
domain and constrain the possible
interpretation of terms.”
(Jasper &
Ushold, 1999, p. 000)