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Publication - Professor David Blockley

    Uncertainty - Prediction or Control


    Blockley, D, 2009, ‘Uncertainty - Prediction or Control’. International Journal Engineering under Uncertainty, vol 1., pp. 73 - 80


    Engineering practice involves decision making under extreme uncertainty. The purpose of this paper is to discuss the nature of uncertainty from first principles, to consider its various manifestations and to suggest ways in which we can improve. From first principles six kinds of uncertainty are identified under the headings of truth, trust, clarity, changeableness, incompleteness and risk. It is argued that truth and changeableness (together as one kind) with clarity and completeness are three central attributes of information and that trust is central to the making of decisions by ‘experts’. They all are ingredients of the main task of managing and controlling risk. Reductionism has been successful for the analysis of hard systems but soft systems are governed by the behaviour of people which is so complex as to be hard to define and difficult to analyse. The emphasis in soft systems therefore is not on prediction but rather on managing a process to achieve desired outcomes based on dependable evidence which is context dependent. Processes are the way things behave in hard systems and what people do in soft systems.

    Full details in the University publications repository