Commonly-used coreference metrics such as MUC (Vilain et al., 1995) and B 3 (Bagga and Baldwin, 1998) do not have this property, so we instead make use of a parameterized loss function that does and fit the parameters to give good performance.
we take where c 1 , c 2 , and c 3 are real-valued weights, K 1 denotes the event that a i is falsely anaphoric when it should be non-anaphoric, K 2 denotes the event that a i is falsely non-anaphoric when it should be anaphoric, and K 3 denotes the event that a i is correctly determined to be anaphoric but .