Performance of dual-polarized radio links operating in the microwave and millimeter wave regions is affected by the propagation medium. The attenuation ( 

 ) and cross-polarization discrimination (XPD) are used to quantify the medium effects. Of particular importance is the XPD versus 

 relationship. Three ways of displaying XPD versus 

 data are examined: mean, median, and equiprobable. It is shown that mean and medium are essentially identical measures, whereas equiprobable is sensitive to several error sources and is especially sensitive to ice depolarization. It is concluded that XPD versus 

 data sets using mean and median can be safely compared, but equiprobable results must be treated with caution.