Fourty years of the Šesták–Berggren equation

The Šesták–Berggren equation, representing a powerful tool for the description of kinetic data by the model-fitting methods, is analyzed. It is discussed that the exponents in the conversion function are non-integer in general and that the conversion function may not have a mechanistic interpretation. Within the framework of single-step approximation, the Šesták–Berggren equation enables to describe the kinetics of complex condensed-state processes without a deeper insight into their mechanism.