# Separation Method

In the Advanced tab of the Jitter Measurement Setup dialog box, in the Random Jitter/Interference (RJ/RN) area, the Separation Method tab has these options to let you specify the method used to measure random jitter or random interference:

- Auto — Automatically chooses between the Spectral and Tail Fit methods based on the perceived amount of BUJ/BUI.

- Spectral — This method gives accurate results, but incorrectly characterizes BUJ/BUI as RJ/RN. Results are calculated using the aliased spectrum.

- Tail Fit — This method is less accurate than the Spectral method, but it is better at distinguishing BUJ/BUI. Results are calculated using the tails of the histogram.