For acquiring and evaluating measured variables which are critical for safety, e.g. yaw rates (GR), as input variables of a motor vehicle control system, the measured variables are obtained by means of two mutually independent measuring channels (M1, M2) of which one measuring channel (M1) acquires the entire range to be measured whilst the other measuring channel (M2) is set at a partial range. In order to detect errors, the output variables of the measuring channels (M1, M2) are checked for conformance of the measured variables acquired by the measuring channels and/or for plausibility of the measurement results.