No plea about inadequacy of our understanding of the decision-making processes can excuse us from estimating decision making criteria. To omit a decision point is to deny its presence – a mistake of far greater magnitude than any errors in our best estimate of the process.

Forester (2000) "Perspectives on the modelling process" in: Modeling for Learning Organizations. John Douglas William Morecroft, John Sterman eds. 2000. p. 66