Abstract: A method for providing a condition evaluation of a mechanical structure which includes a rotating machine component includes providing an input signal that represents mechanical vibrations in the mechanical structure and selecting, on the basis of the input signal and a number of reference signals, one among a plurality of predetermined condition evaluations for the mechanical structure. When the rotating machine component includes a gear transmission, the condition evaluation is selected using amplitude demodulation. When the machine component includes a rotating bearing, the condition evaluation is selected using cross-correlation.