warming models
> Ray,
> Further, from my
> readings on statistical models, the only real test of a model is how well
> its *predicitions* match up with the real data.
>
> Steve
Perhaps. The only way a model can be 'validated' is to run the model using
an 'independent' data set. This type of data set would have to be different
than the data set used to 'calibrate' the model. Time can only tell which
models are accurate and which ones are not.
Ray, again you are using the term "valid" when you mean "reliable." Validity
refers to the "Truth" (with a capital 'T'). What you mean is how well the
model runs using various data sets; i.e how reliable it is. I do not
question the reliability of the computer models, indeed I know nothing of
them at all, but I worry that policy will or will not be made based on this
confusion of validity for reliability. If you recall in the George Bush's
(the elder) administration there was a cessation of all work on global
warming policy because his chief of staff (I forget his name, he was a Ph.D.
engineer from New Hampshire?) disagreed with the models so he said there was
no "evidence" for global warming. He mistook reliability for validity.
Steven
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