PRINCIPLES OF MODELLING 5
9. A model cannot be better than the information that goes into it.
Garbage In, Garbage Out (GIGO) is very applicable to modeling.
Also, models do not create information, but condense or convert information.
In some cases, instead of exerting one's efforts on model construction, one would be better off just gathering more information about the real system.
Be careful that you don't put in too much information.