ONTOLOGY REUSE: BETTER SAFE THAN SORRY
Bernardo Cuenca Grau, Ian Horrocks, Yevgeny Kazakov, Ulrike Sattler · 2007
The design, maintenance, reuse, and integration of ontologies are complex tasks. Like software engineers, ontology engineers need to be supported by tools and methodologies that help them to minimize the introduction of errors, i.e., to ensure that ontologies are consistent and do not have unexpected consequences. In order to develop this support, important notions from software engineering, such as module, black-box behavior, and controlled interaction, must be adapted. Recently, there has been growing interest in the topic of modularity in ontology engineering [10, 9, 8, 5, 3], motivated by the above mentioned application needs. This paper extends our previous results[3]. We focus on the problem of “safe” reuse of ontologies and consider the scenario in which we are developing an ontology P and want to reuse a set S of symbols—that is, concept names, role names and individuals— from a “foreign” ontology Q without changing their meaning. Suppose that an ontology engineer is building an ontology about research projects, which specifies different types of projects according to the research topics they focus on. For example, the concepts Genetic Disorder Project and Cystic Fibrosis EUProject describe projects about genetic disorders and European projects about cystic fibrosis respectively, as given by the axioms P1 and P2 in Figure 1. The ontology engineer is an expert on research projects; he knows, for example, that every instance of EU Project must be an instance of Project (axiom P3) and that the role has Focus can be applied only to instances of Project (axiom P4). He may be unfamiliar, however, with most of the topics the projects cover and, in particular, with the terms Cystic Fibrosis and Genetic Disorder mentioned in P1 and P2. In order to complete the projects ontology with suitable definitions of these medical terms, he decides to reuse the knowledge about these subjects from a well-established medical ontology. Suppose that Cystic Fibrosis and Genetic Disorder are described in an ontology Q containing axioms M1-M4 in Figure 1. The most straightforward way to reuse these concepts is to import in P the ontology Q—that is, to add the axioms from Q to the axioms of P and work with the extended ontology P ∪Q. Importing additional axioms into an ontology may result into new logical consequences. For example, axioms M1– M4 inQ imply that every instance of Cystic Fibrosis is an instance of Genetic Disorder: