Linear operators are used as a statistical tool in the analysis of seismic records. It was found that when an operator is chosen for a non-reflection interval and applied to regions during which reflections occur, the effectiveness of the operator is disturbed and large errors of prediction result. This effect provides a method for the discrimination of reflections. The technique used has its basis in the theory of time series, relevant concepts of which are reviewed. The mechanics of application are given, and illustrative examples on ten seismograms are presented.