We describe a tool which supports the activity of a human being in fitting
a mathematical model to measured or simulated data. The tool offers two pri
ncipal advantages; its use requires a minimum of statistical knowledge, and
its visual and interactive nature ensures that its use is intuitive. The t
ool is novel in that, in the iterative and often exploratory construction o
f a model, it represents,graphically the benefit of all possible single cha
nges to the existing model; a single selection action suffices to add a new
term to a model or to remove it. Copyright (C) 2001 John Wiley & Sons, Ltd
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