To characterize the polarimeter it is necessary to know the 
,
however, finding the greatest 
does not optimize the performance
of the polarimeter. Instead it is necessary to maximize a quantity called
figure-of-merit (FOM) which, for polarimeters, is often defined as
where N is the total number of events counted in the detector. When FOM
is maximized the uncertainty in the measured neutron polarization is
minimized. This is done by applying a number of cuts to the final reduced
data set (described in section 
) to get the best results, as
defined by FOM. The cuts which are applied to the data are described below.
