  In this paper, we present a framework for assessing the effect of
non-stationary Gaussian noise and radio frequency interference (RFI) on the
signal to noise ratio, the number of false positives detected per true positive
and the sensitivity of standard pulsar search pipelines. The results highlight
the necessity to develop algorithms that are able to identify and remove
non-stationary variations from the data before RFI excision and searching is
performed in order to limit false positive detections. The results also show
that the spectrum whitening algorithms currently employed, severely affect the
efficiency of pulsar search pipelines by reducing their sensitivity to long
period pulsars.
