The disclosure relates to a method and apparatus for displaying changes in parameter values on a display surface. Two successive sampled values (P11, P12 and P21, P22) of, in each case, two parameter values (P1, P2) are represented as oppositely directed vectors with a common origin orthogonally with respect to a dividing line which divides the display surface and that area which is enclosed by the dividing line and the connecting lines between the respectively older sampled value (P11 and P21) of a parameter value (P1, P2) and the respectively more recent sampled value (P12 and P22) of the other parameter value (P2, P1) is highlighted.