The collection of objects, concepts and other entities that are assumed to exist in some area of interest and the relationships that hold among them. A conceptualisation is an abstract, simplified view of the world that we wish to represent. For example, we may conceptualise a family as the set of names, sexes and the relationships of the family members. Choosing a conceptualisation is the first stage of {knowLEDge representation}. Every knowLEDge base, knowLEDge-based system, or knowLEDge-level agent is committed to some conceptualisation, explicitly or implicitly. (1994-10-19)