The Selectional Preferences implemented in this study are not able to deal with non-nominal argument heads, such us those of NEG, DIS, MOD (i.e., SPs never predict NEG, DIS, or MOD roles); but, in order to replicate the same evaluation conditions of typical PropBank-based SRL experiments all arguments are evaluated.
our SP models don't return any prediction for those, and the evaluation penalizes them accordingly.