A method for evaluating abnormal combustion events of an internal combustion engine of a motor vehicle by regression calculation of a physical reference variable, in which method a recognition variable of the abnormal combustion event is calculated from a measured sensor signal. In a method with which abnormal combustion processes of the internal combustion engine can be reliably recognized and classified at all operating points, a stepwise system is used for regression calculation of the recognition variable, in which system at least one reference variable that corresponds to a measured reference variable of the sensor signal is calculated from the sensor signal.