For example, the law PV = RT relating pressure P, volume V and temperature T of an "ideal" gas via a constant R is not exactly true for any real gas, but it frequently provides a useful approximation and furthermore its structure is informative since it springs from a physical view of the behavior of gas molecules.įor such a model there is no need to ask the question "Is the model true?". However, cunningly chosen parsimonious models often do provide remarkably useful approximations. Now it would be very remarkable if any system existing in the real world could be exactly represented by any simple model. The paper contains a section entitled "All models are wrong but some are useful". It is inappropriate to be concerned about mice when there are tigers abroad.īox repeated the aphorism in a paper that was published in the proceedings of a 1978 statistics workshop. Since all models are wrong the scientist must be alert to what is importantly wrong. Just as the ability to devise simple but evocative models is the signature of the great scientist so overelaboration and overparameterization is often the mark of mediocrity. On the contrary following William of Occam he should seek an economical description of natural phenomena.
Since all models are wrong the scientist cannot obtain a "correct" one by excessive elaboration. The two sections of the paper that contain the aphorism are copied below. The 1976 paper contains the aphorism twice. The first record of Box saying "all models are wrong" is in a 1976 paper published in the Journal of the American Statistical Association.
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