No, that does not work at all. Patching together a model to suite a symptom in retrospect does not help you with being ready for unexpected eventfulness in nature that you previously had no idea that you should be looking for.
Phil Henshaw ¸¸¸¸.·´ ¯ `·.¸¸¸¸ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 680 Ft. Washington Ave NY NY 10040 tel: 212-795-4844 e-mail: [EMAIL PROTECTED]: www.synapse9.com in the last 200 years the amount of change that once needed a century of thought now takes just five weeks > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of Marcus G. Daniels > Sent: Saturday, April 26, 2008 10:45 AM > To: The Friday Morning Applied Complexity Coffee Group > Subject: Re: [FRIAM] recap on Rosen > > phil henshaw wrote: > > Ok, 'find a function' assumes there is one to find, but the problem > set is > > running into behavior which has already had major consequences (like > > starvation for 100million people because of an unexpected world food > price > > level shift) and the question is what 'function' would you use to not > be > > caught flat footed like that. > The caloric requirements of a person are autocorrelated, but probably > for a lot of models a constant will suffice -- a certain amount of body > weight decrease, and then the probability of death goes up. As for > price fluctuations, that's a matter of modeling the natural resources > that go in to food, the costs and benefits to motivate farmers, the > commodity markets, and so on. Certainly we can try to understand how > each of these work, and then do what-if scenarios when one or more > components are perturbed (or destroyed). It's still a matter of > finding stories (functions) to fit observables. The availability and > accuracy of those observables may be poor, and sometimes all that is > possible to imagine worst and best cases, run the numbers, and see how > the result changes. > > Is there some general function to use in > > cases where you have no function and don't even know what the problem > > definition will be? > > > I think you do know what the problem could look like, but most details > remain unspecified. If you can construct an example that has > catastrophes of the kind you often talk about, and spell out all of the > details of your work of fiction (that even may happen to resemble > reality), such that the what-if scenarios can be reproduced in > simulations, then others can study the sensitivities. If there is a > `forcing structure' that will occur in many, many variant forms, then > you can demonstrate that. > > I actually have a very good one, but you won't like it because it > means > > using the models to understand what they fail to describe rather than > the > > usual method of using them to represent other things. > Right. Model predicts something, it turns out to have some error > structure and that structure suggests ways to improve the model or make > a new one. Paper published. Meanwhile another guy makes a different > model on the same phenomena and publishes a paper. Third person reads > the two papers and has idea that accounts for problems in both. So > she > makes a new model! > > Marcus > > > ============================================================ > 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 ============================================================ 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
