The reality of information systems research - Information Systems Foundations: Constructing and Criticising - page 27

models they create. While these approaches reflect the diversity of perspectives in in-
formation systems, they deal with different units of analysis. Rather than examining a
possibly hypothetical system and the processes and entities that exist in that system,
we are examining things that exist in reality, and such a study has its roots in ontology.

Ontology
Within philosophy, ontology is the study of things that exist; the objects, properties,
categories and relations that make up the world. A definition of ontology as it is conceived
by philosophers is:
… the science of being in general, embracing such issues as the nature of ex-
istence and the categorial structure of reality. … Different systems of ontology
propose alternative categorial schemes. A categorial scheme typically exhibits
a hierarchical structure, with 'being' or 'entity' as the topmost category, em-
bracing everything that exists (Honderich, 1995).
This approach to the definition and use of ontology has also been successfully applied
in information systems, for example in comparing and evaluating data modelling
frameworks (Milton, 2000; Milton and Kazmierczak, 2004).
Philosophers distinguish between reference ontologies, which aim to determine the
fundamental categories and categorial structures, and domain specific ontologies, where
a particular reference ontology is applied to a certain problem domain. An analogy could
be made between the way that ontologies and data models are conceptualised, as shown
in Table 3.1.
Table 3.1. Ontologies and data models
Data model Ontology

Reference ontology Data modelling language

Domain specific ontologies Data models

Specific reality Database implementation of specific database

instances

Reference ontologies
Reference ontologies, such as that of Bunge (1977; 1979), Chisholm (1996), Basic Formal
Ontology (Smith, 1978; Smith and Mulligan, 1983) and DOLCE (Gangemi, et al., 2002)
are concerned with the most general categories of what there is in the world. They deal
with concepts such as thing , individual and property . In the analogy proposed in Table 3.1,
data modelling languages such as entity-relationship modelling are proposed as analogous
to reference ontologies.

Domain specific ontologies
At this level, particular reference ontologies are used to create a domain specific ontology
directed towards an aspect of reality, in the way that particular data modelling languages
are used to create data models of a particular project, such as a university student records
system or a banking system. Early artificial intelligence (AI) focus was at this level.

Ontology and artificial intelligence
At this point we note that AI researchers have a particular view of ontology, referring
to it as
… an engineering artefact, constituted by a specific vocabulary used to describe
a certain reality, plus a set of explicit assumptions regarding the intended
meaning of the vocabulary words (Guarino, 1998).