In science, a model is an aid to understanding that represents an unseen or complex phenomenon.[1]
Models can be empirically found, or they can be derived from fundamental laws. A good model has a well-defined domain of validity, in which it leads to unambiguous, self-consistent results. Ideally it is easy to evaluate. To adaption of a model to a specific problem instance is done by model parameters, which can be defined/measured independently or left as free parameters to fit the model to a realistic situation. A large number of free parameters makes it difficult to assess the validity of the model without independent knowledge.
One can also make a model simply by fiddling around with the data, that is, "curve fitting" without a fundamental understanding of the phenomenon, as NASA did when studying the erosion of O-rings used in the space shuttle:
Categories: [Science]