model

...managers are facing increasing demands to produce quantitative predictions of population responses to disturbances, such as harvesting. Prediction requires some sort of model, whose development is annoying but challenging.

[C. Walters, Adaptive Management of Renewable Resources, New York: Macmillan Publishing Company, 1986, pp. 129]

annoying and challenging are both negative terms for me .... so what's the catch?? *sigh*