We view the cognitive system as a system that aims at interpreting the world. This interpretation involves the categorisation and structuring of information. Particularly important for a successful categorisation and information structuring is the disregard of irrelevant data. Underspecification, understood as 'purposeful' neglect of such information in conceptualisation, provides a mechanism for this, a mechanism that is a vital part of our cognitive system. It allows us to disregard dispensable information, whereby the cognitive effort is kept low.