In the field of electronic or computerized control apparatuses, known methods of compensating for disturbance signals rely on less than ideal analytical or empirical models. There is provided a controller (200) or method of controlling which observes and learns the correlation between various measured signals and automatically learns how to control the apparatus. It has a primary input (x.sub.R) for the measured state of the apparatus, and signal processing means (604, 606) responsive to the input signal for generating a control signal (V) to maintain the apparatus in a desired state, the controller (200) having further input(s) (X.sub.1, X.sub.a) for additional measurements of the apparatus or its environment the signal processing means using a weighted average (606) of results of different fixed impulse responses (611-615) to each input to modify the control signal, and means (630, 800, 802) for conditioning the response automatically in response to temporal cross-correlation observed between the measurement signal(s) and the control signal. The controller can be pre-taught with an appropriate response, or it can learn it during initial operation.