Ontology Construction - Enterprise Information Systems Design, Implementation and Management: Organizational Applications - page 58

the current state of the art in ontology design
(Baptista et al., 2004).

systems), systems specification, requirements
identification, inter-operability and the potential
for reuse and sharing (Uschold & Gruninger,
1996). Formal definitions include:

ontoLogies

• “ An Ontology is an explicit specification

of a conceptualization .” (Gruber 1995, pp.
907);

The first ontologies consisted in practical ex-
amples, built from scratch and made available
in order to demonstrate the usefulness of such
technology. By that time no methodologies or
guidelines were available to lead or ease the build-
ing process. After some experience on the field,
Gruber (1993), introduced some principles for the
design of ontologies. Gruber's work was the first
to describe the role of ontologies in supporting
knowledge sharing activities, and presented a set of
guidelines for the development of ontologies. The
ontology-building process became clearer, with the
continuous development of several other ontolo-
gies. As a consequence, the first methodologies
for building ontologies appeared in 1995, leading
to the emergence of the ontological engineering
field (Baptista et al, 2006).

• “ An Ontology is a theory of what entities

can exist in the mind of a knowledgeable
agent .” (Wielinga and Schreiber, 1993);

• “ Ontologies are agreements about shared

conceptualizations. Shared conceptualiza-
tions include conceptual frameworks for
modeling domain knowledge; content-spe-
cific protocols for communication among
inter-operating agents; and agreements
about the representation of particular do-
main theories. In the knowledge-sharing
context, ontologies are specified in the
form of definitions of representational vo-
cabulary. A very simple case would be a
type hierarchy, specifying classes and their
subsumption relationships. Relational da-
tabase schemata also serve as ontologies
by specifying the relations that can exist
in some shared database and the integ-
rity constraints that must hold for them ”
(Gruber, 1994);

What is an ontology

The term “Ontology”, dated circa 1721 (Merriam-
Webster, 2008), in its abstract philosophical no-
tion can be defined as “a branch of metaphysics
concerned with the nature and relations of being”
(Merriam-Webster, 2008), “a particular theory
about the nature of being or the kinds of things
that have existence” (Merriam-Webster, 2008).
As early as 1900, the notion of a formal ontology
has been distinguished from formal logic by the
philosopher Husserl (Smith, 1998).
The term “Ontology”, in Artificial Intelligence,
is used to refer to the shared understanding of
some domain of interest which may be used as
a unifying framework to identifying important
underlying concepts, define them, assign terms
to them and note their important relation-ships,
improving shared understanding, communica-
tion (among organizations, people and software

• “ An Ontology is a explicit knowledge level

specification of a conceptualization, (...)
which may be affected by the particular
domain and task it is intended for .” (van
Heijst, Schreiber and Wielinga 1996, pp.
11);

• “ An Ontology is an explicit, partial ac-

count of a conceptualization .” (Guarino &
Giaretta, 1995, pp. 26);

• “ An Ontology for a body of knowledge

concerning a particular task or domain
describes a taxonomy of concepts for that
task or domain that define the semantic in-
terpretation of the knowledge. ” (Alberts,
1993, cited by Sierra et al, pp. 34);