Lately I have been doing simulations of wildfires. The program that I have been using (Farsite) is based on first principles of fire physics. Assuming that the inputs are correct (elevation, slope, aspect, fuel, canopy, wind, temperature, humidity and a few others) I suspect the estimate of the fire area as a function of time, and even the footprint represents a fairly accurate prediction.
Maybe there is a definition of "complex system" that is related to the question of what kinds of predictions simulations of them can yield? Frank --- Frank C. Wimberly 140 Calle Ojo Feliz (505) 995-8715 or (505) 670-9918 (cell) Santa Fe, NM [EMAIL PROTECTED] -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Robert Holmes Sent: Tuesday, August 08, 2006 1:17 PM To: FRIAM Subject: [FRIAM] Simulation and policy-making Here's a quote from a letter in this week's Economist about how to use big economic models: The root of many problems lies not in the [economic] models themselves but in the way in which they are used. Too often we ask "What will happen?", trapping us into the mug's game of prediction, when the real question should be: "Given that we cannot predict, what is our best move today?"...Instead of determining the "best" model that solves optimal strategies we should instead seek the most "robust" model that achieves a given level of "goodness" across myriad models and uses assumptions consistent with known facts. My colleagues and I use such methods to address intractable policy issues fraught with arguments over which model is "right", what assumptions are valid and what is the nature of the good? This method makes the decision to be informed part of the analysis itself and the results are more readily accepted by policymakers. That was from a senior economist at RAND. So it looks as if at least some members of the current military-industrial complex are using simulations in a sensible and valid way (certainly with more sense and validity than a lot of the academic papers I see). So if 'valid' simulations are being used to give the 'wrong' answers, what does that tell us about simulation? Is there ever any hope of objectivity (I'll give away the answer to that: no) or do all social simulations - political or economic - inevitably reflect the prejudices of their author or funder? Robert ============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
