The acquisition of knowledge about systems and the processing of information about them are key features of modern control engineering technology. This is the theme for a volume of articles setting out the scope and content to be covered at the European Control Conference (ECC '93) in Groningen, the Netherlands. The book provides a broad overview of the field of control and a discussion of its development both from a theoretical and an engineering perspective. It contains the fully developed articles on which the plenary addresses and mini-courses of the Conference are based.