Ontologies are formal, structured representations of knowledge within a domain, modelled as the types of concepts or objects which exist within that domain, together with their properties and relationships. They are widely used in knowledge management systems, for functions as varied as automated reasoning, recommendation systems, and faceted searching and browsing, and they form an integral part of the Semantic Web. Ontologies are most effective in knowledge domains with an agreed common terminology and a shared understanding of the semantic and conceptual structures of the domain.
This paper will examine issues related to the deployment of ontologies in digital infrastructure for the humanities. Processes for naming, describing and categorizing phenomena are fundamental to research in these disciplines, while interpretation and framing are also central. Ontologies are therefore potentially very valuable for structuring discourse and analysis. But the use of ontologies in the humanities raises a number of important difficulties.
Some of these are primarily linguistic in nature. The same concept or phenomenon may be described using different terms by different researchers. The same term may be capable of referring to different concepts or phenomena, depending on the context. The understanding of a knowledge domain is likely to have changed dramatically over time, along with the vocabulary used. Much humanities research involves languages other than English, either for the subject of the research or for the research discourse itself.
There are important conceptual and semantic differences between the various humanities disciplines, as well as between researchers within a single discipline. This is reflected in the terminologies, vocabularies and intellectual models they use. While a common ground is essential for interdisciplinary communication, it is difficult for traditional ontologies to provide such a bridge. Most upper-level interdisciplinary ontologies are too generalized, while domain-specific ontologies are too narrow.
Does this mean that ontologies are ineffective for interdisciplinary research in the humanities? Are specialized vocabularies the most we can aim for? Do we have to fall back on purely linguistic associations discovered through keyword and phrase searches? Is it inherently impractical to build knowledge management systems of the kind developed for scientific disciplines?
This paper will discuss these questions, drawing particularly on experiences gained during the Humanities Networked Infrastructure (HuNI) project. It will offer some suggestions for the use of ontology-like approaches in the humanities, aimed at building a network of semantic assertions, which embody a range of different perspectives on knowledge and provide a foundation for future interdisciplinary research and development.