Main concepts: concepts, knowledge and operators

C-K theory focuses on one of the most troubling aspects of theoretical approaches to design: the difficulty of defining the starting point of a design task; what professionals call "specifications", "programs", "briefs". It's a question of describing an object by giving only certain desirable properties, without being able to give a constructive definition of this object, and without being able to guarantee its existence on the basis of pre-existing knowledge. Whereas mapping-type design theories (such as problem-solving, optimization and programming approaches, derived in particular from the Simonian approach to design) tend to assimilate design to a search in a known space (which may be complex or even uncertain), C-K...