Abstract: The invention is directed to a method for diagnosing the state of a system. The system may be mechanical, chemical, electrical, medical, industrial, business operations, manufacturing related, and/or processing related, among others. The method may measure a signal from the system. Further, the method may compare the signal to an expected signal. The method may calculate a signal strength and/or a noise. The signal strength and noise may be functions of a frequency. Further, the signal strength and noise may be used to determine a channel capacity and/or a rate of information. A comparison of the rate of information and the channel capacity may yield information associated with the state of the system. The information may be used in diagnosing the state of the system. Further, the expected signal may be derived from a model. The model may be tuned to the measured signal. The model may have parameters that are associated with features and/or faults of the system.