Multiples as well as primaries will give rise to peaks and hence the results have to be interpreted to determine the best values to be used to stack the data. In many areas where the velocity increases more-or-less monotonically with depth, the peaks associated with the highest reasonable stacking velocities are assumed to represent primary reflections and peaks associated with lower velocities are attributed to multiples of various sorts. In other areas the relationships are not as obvious and even where the velocity relationships are generally regular, difficulties will be encountered.