Who Produced the Model

The common perception among environmental practitioners, that a modeling program produces a model, is not correct. It is always the modeler, not the computer code, that produces a model. In environmental practice, this misconception, and sometimes misrepresentation, borders on deception of the public, regulators, or clients because most popular modeling codes are distributed by regulatory or federal agencies and therefore carry an air of authority. 

In summary, a model is invariably produced with certain input from the modeler, even though the need for conceptualization on the modeler s part is not always apparent. The modeling programs and databases have not been tested for the accuracy and completeness of their thermodynamic properties. Sometimes, running the code without worrying about the underlying conceptualization produces acceptable modeling results. Often, however, we are not that lucky, and it is the modeler s responsibility to ensure that the results are produced from an acceptable chemical model. 

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