The Onomasiological approach and the function of definitions in the elaboration of domain models in ontologies

The capture of Knowledge for the elaboration of domain models can take a semasiological approach from a linguistic perspective (from term to concept) or an onomasiological approach, from an extra linguistic perspective (from concept to term). In this article, we support the onomasiological approach devised by I. Dahlberg and we demonstrate the roles played by definitions in this activity. A definition, in this sense, is understood as the product of an agreement established between the modeler/ontologist and the domain expert; it reflects the intended model of representation of the modeled world. Introduction Domain models are obtained from processes aimed at high quality representation of knowledge of selected phenomena in a certain domain. In recent years, informational ontologies have been considered as formal systems to represent knowledge in a given domain, thus acting as a formal model to systematize the expression of the knowledge they manipulate. Since the 1990s, they have been conceptualized as an explicit specification of a conceptualization (Gruber 1993a). Formally, an ontology is a statement of a logical theory defining the set of representation primitives used to model a knowledge domain, such primitives being classes, attributes, and relations. Definitions explain this understanding, while formal axioms restrict interpretation (Santos 2010). Domain models resulting from these conceptualization operations in informational ontologies can be defined as models that represent knowledge of an application area (subject area, mission area or problem area) and which should serve as a consensus representation (or model of reference) of a conceptualization shared by a given community. In order to conduct a conceptualization, we shall refer to I. Dahlberg’s concept theory, keeping in mind the referent, to present the procedure of how to capture domain knowledge via an extra linguistic approach. This method is established within an onomasiological approach. In this way, we present the roles that definitions play in this process: they are at the same time elements that allow the capture of knowledge about a domain, but are also the products of an agreement established between the modeler/ontologist and the domain expert for elaboration of the intended representation model of the modeled world. This article is organized as follows: To begin with (after this introduction), we present the types of definition in ontologies. We will then discuss procedures for