We define a model as a adequate and dependable instrument. The adequacy and dependability of an instrument is based on a judgement made by the community of practice. An instrument has a background consisting of an undisputable grounding from one side (paradigms, postulates, restrictions, theories, culture, foundations, conventions, authorities) and of a disputable and adjustable basis from other side (assumptions, concepts, practices, language as carrier, thought community and thought style, methodology, pattern, routines, commonsense). This implies an profile and an anti-profile (prohibited use) for the use of a model.
http://www.is.informatik.uni-kiel.de/en/is/miscellaneous/mmm/
http://www.is.informatik.uni-kiel.de/thalheim/ModelsToModelModellingThalheimCollection.pdf
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