You may be interested in a paper of medium age I just read. Testing ecological models: the meaning of validation (PDF) tackles a problem many of you are familiar with in a slightly different context.
To entice you to read it, here are some quotes from its descriptions of other papers:
Holling (1978) pronounced it a fable that the purpose of validation is to establish the truth of the model…
Overton (1977) viewed validation as an integral part of the modelling process…
Botkin (1993) expressed concern that the usage of the terms verification and validation was not consistent with their logical meanings…
Mankin et al. (1977) suggested that the objectives of model-building may be achieved without validating the model…
I have another reason for posting this; I’m looking for more papers on model validation, especially how-to papers. Which ones do you consider most helpful?