Enthalpy-entropy compensation: a phantom phenomenon.

Enthalpy-entropy compensation is the name given to the correlation sometimes observed between the estimates of the enthalpy and entropy of a reaction obtained from temperature-dependence data. Although the mainly artefactual nature of this correlation has been known for many years, the subject enjoys periodical revivals, in part because of the frequent excellence of the correlation. As with other cases of impossibly good correlation between two biological variables, the explanation is that what purports to be two variables are very largely the same variable looked at in two different ways.