Ontologies

Abstract

Aßmann et al. (2006, p. 253), quoting Gruber (1993), state that an ontology is a formal specification of a shared conceptualisation. Since it is both an abstraction and a simplification of some reality (domain of interest), an ontology is also a model (e.g. Nirenburg 2004; Guizzardi 2005, p. 6; Aßmann et al. 2006, p. 256) but one that is descriptive, domain-relevant and static as opposed to a system-focussed model, which does not require any shared understanding nor does it model the whole of the domain (Fig. 5.1). It is widely stated that, while an ontology uses an open-world assumption, a model uses a closed-world assumption (e.g. Aßmann et al. 2006; Atkinson et al. 2006) although some ontologies are based on a closed-world assumption (e.g. Wang et al. 2006).