Let indicate the probability that a span of form (t 1 ) r (t 2 ) extracted from sentence s is coherent.
we model p(c = 1|s, (t 1 ) r (t 2 )) using logistic regression, with features based on the position of partof-speech tags and dependency edges in s. each sentence in the filtered dataset contains a span of the form (t 1 ) r (t 2 ).