Ontology Development and Evolution in the Accident Investigation Domain

InvestigationOrganizer (IO) is a collaborative semantic web application designed to support mishap investigations, and has been used for accidents ranging from those involving only minor property damage to the loss of the Space Shuttle Columbia. The development and use of IO in support of these investigations has provided significant lessons about the use of semantic web technologies in real-world systems. IO is a data and knowledge repository for a wide range of mishap related information in which investigators meaningfully structure information and link together evidence, causal models, and investigation results. The types of knowledge that investigators can include in the repository are defined by its investigation ontology, a component of the system that expresses investigation concepts using a logical formalism. IO developers can dynamically alter this ontology without having to recompile the application. This paper describes the development of the investigation ontology for IO, focusing on its growth in response to user needs during the investigations, as well as efforts to control that growth.