1. A method for providing a characteristic quantity for a state of an air system of a supercharged internal combustion engine for control of said engine, comprising: detecting, with the aid of a sensor, a characteristic quantity measured value; providing a characteristic quantity model, wherein a characteristic quantity model value is computed on the basis of at least one quantity different from the characteristic quantity measured value; and providing a characteristic quantity information based on one of the characteristic quantity measured value or the characteristic quantity model value computed based on the characteristic quantity model, as a function of a state of the air system.