In order to exploit relevant information about a specific domain, the domain vocabulary must be captured. In addition, rigorous definitions of the basic terms in the vocabulary and the logical connections between those terms must be identified. Ontologies are used to capture the concept and objects in a specific domain, along with associated relationships and meanings. In addition, ontology capture helps coordinate projects by standardizing terminology and creates opportunities for information reuse. The lDEF5 Ontology Capture Method has been developed to reliably construct ontologies in a way that closely reflects human understanding of the specific domain. lDEF5 relies on iterative knowledge extraction through various steps: organizingiscoping; data collection; data analysis; initial development; ontology refinement/validation. lDEF5 allows users to validate the vocabulary and axioms of a given domain and store that knowledge in a usable representational medium.