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This chapter compares results from the Canadian global ensemble Kalman filter (EnKF) with observations. This inevitably leads to discrepancies between the observed real atmosphere and its modelled equivalent. These discrepancies originate from system error. In a system simulation experiment, an attempt is made to obtain a coherent picture of the error evolution of a system. Errors can be due to things as different as an inappropriate closure assumption in a forecast model and inaccurate observations of surface pressure. This chapter first describes Monte Carlo methods in general to arrive at a definition of ‘system error’. This is followed by an elimination procedure. First, medium-range ensemble forecasts are used to quantify the understanding of weaknesses of the forecast model. Subsequently, consideration turns to the data-assimilation context to see what additional error sources must be present. The chapter ends with some speculation on the types of errors that should be included.

This chapter, compares results from the Canadian global ensemble Kalman filter (EnKF) with observations. This inevitably leads to discrepancies between the observed real atmosphere and its modelled equivalent. These discrepancies originate from system error. In a system simulation experiment, an attempt is made to obtain a coherent picture of the error evolution of a system. Errors can be due to things as different as an inappropriate closure assumption in a forecast model and inaccurate observations of surface pressure. This chapter, first describes Monte- Carlo methods in general to arrive at a definition of “‘system error”.‘. This is followed by an elimination procedure. First, medium-range ensemble forecasts are used to quantify the understanding of weaknesses of the forecast model. Subsequently, consideration turns to the data-assimilation context to see what additional error sources must be present. The chapter ends with some speculation on the types of errors that should be included.

This chapter starts with the different definitions of the term “glitch” in different fields, specifically in electronic, circuit-bending, and software industries. It explains the glitch concept in the field of software as an unpredictable and unavoidable error in the behavior of the system. Glitches, or bugs, manifest the authenticity of software aesthetics. The chapter explains that a glitch can be software or hardware jargon and examines the common situations of occurrence. The later parts of the chapter emphasize the impact of glitches in computer technology, media art, designing, and various other fields.

we are almost halfway through the book and this part on design ecology, and I have yet to talk about design, no less software engineering. Is this some kind of shaggy dog story? The kind in which the hero climbs mountains in search of the meaning of life only to have the wise man tell him it is, “The wet bird flies at night.” I hope not. Here is the basic thesis of the book. Computers offer unprecedented power in creating new tools (equipment), but to achieve their potential we must reconstruct how they are used (i.e., shift the paradigm). The first half of the book concerns the foundations upon which we may reconstruct a new software engineering. In the middle of this century, of course, there would be no question as to what that foundation should be: science. But, as I have been trying to show, science and our institutions are in a period of fundamental change. For example, consider what Prigogine, winner of the 1977 Nobel Prize for chemistry, has to say.… The classical … view of science was to regard the world as an “object,” to try to describe the physical world as if it were being seen from the outside as an object of analysis to which we do not belong… The deterministic laws of physics, which were at one point the only acceptable laws, today seem like gross simplifications, nearly a caricature of evolution.… Even in physics, as in sociology, only various possible “scenarios” can be predicted. But it is for this very reason that we are participating in a fascinating adventure in which, in the words of Niels Bohr, we are “both spectators and actors.” (1980, pp. xv, xvii)… Thus, in only four decades we have moved from physicalism, which sought to impose a physics model on psychology, to a questioning of the very nature of physics itself. As Holland, a physicist, describes our present situation, “we are in a period of transition between two great world views—the universal machine of the classicists and the new holistic universe whose details we are only beginning to glimpse.