8.2.1 Definition and Purpose of the Ontology
The term ‘ontology’ is usually defined as a formal description of the knowledge in a domain. However, there are two variants of this definition. First, ‘ontology’ can refer to a full description of all the knowledge, so that it can be represented and used within a computer system. Second, ‘ontology’ can refer to a generic model that applies to a class of domains. It is the latter definition that will be used here.
Whichever definition one uses, an ontology is most often conceptualised as comprising three main elements: (1) a set of knowledge objects; (2) a set of relations that form associations (relationships) between the knowledge objects; (3) a set of axioms that provides rules and constraints for the relationships (e.g. if A is next to B, then B is next to A). The ontology described here will make use of the first two elements, but not include any axioms, which requires more development.
There are a number of reasons for including an ontology as part of the Personal Knowledge Methodology. First, it can help to integrate and coordinate the use of the Personal Knowledge Techniques for more efficient acquisition of knowledge and facilitation of self-help. Second, the ontology can provide a common underlying language that aids users to understand the information available to them (e.g. from other users) and aids researchers to compare knowledge from different users. Third, the ontology can help the user when searching for, and being presented with, advice from the system. This is achieved by using the ontology to provide key words and semantic tags with which to code the information for searching. Fourth, the ontology provides a structured set of categories that can be used to analyse the knowledge captured from users. Fifth, as multiple users make use of the Personal Knowledge Methodology, the ontology can develop to be a reflection of the commonalities between these users’ lay psychological theories. Sixth, the ontology can be a contribution to the ongoing development of ontologies within knowledge engineering. Finally, a longer-term goal would be to develop multiple versions of the ontology appropriate to different populations that might help to unify various psychological models and theories for intervention and application. It should be stressed that although the ontology may resemble a psychological theory, it would be presumptuous at this stage to consider it as such. However, in the longer term, it is hoped that the ontology can be developed to be a psychological theory.