Abstract
Ontologies aim to represent what is general, by means of universal statements. In contrast, dispositional predications capture knowledge about what is likely to happen if a certain set of circumstances obtain, which is crucial in investigative research such as in drug discovery and systems biology, where entities which are constitutionally dissimilar can nevertheless have similar behavior in a biological context. While such dispositional properties are increasingly included in biomedical ontologies, the circumstances under which the dispositions are realized are seldom explicitly modeled, and doing so is problematic due to the necessary restriction to binary relations in OWL ontologies. In this paper we address this shortcoming, focusing on the bioactivity of small molecules at varying levels of concentration within a living organism as our problem domain, although our approach is generalizable to other problems. We discuss the ontological nature and representation of dispositions and their realization; consider the nature of concentrations and their representation; and finally we detail an approach to linking dispositions to the conditions for their realization which regards conditions as triggers for the process in which the disposition is realized.