In this paper we set α 1 = 2 and α 2 = 1 + σ(P e (v p |r i )), where P e (v p |r i ) is the initial bias of the verb-to-relation mapping.
in this paper we define P (θ) as: We can see from this that σ(P e (v p |r i )) is a conjugate prior on P (v p |r i ; θ) with σ as the confidence parameter.