Although the method of variably compounding seismic reflection records, in order to secure so-called "Controlled Directional Sensitivity" has distinct advantages over the more generally used fixed compounding or so-called "Multiple Recording" and other methods, a simple graphic analysis shows that this "variable compounding" also involves the introduction of adverse effects. Among these are a less directional sensitivity, the production of artificial "noise" which is added to that picked up from the ground, and the magnification of minor waves which the analyzer picks out at random. This graphic analysis shows that, if the two waves arrive simultaneously from different directions, they can be separated if they differ sufficiently in direction and not too much in amplitude. Exception is taken to the use of the term "diffraction" as applied to the wave scattered from the edge of a fault. The method is shown to be superior only in certain special cases, which are, perhaps, rather few.