Therefore, we measure the oracle accuracy of the k-best discourse parser based on the f -scores of the Relation metric, and our reranking framework aims to optimize the Relation metric.
11 the oracle accuracy for k-best parsing is measured as fol- , where N is the total number of texts (sentences or documents) evaluated, g i is the gold DT annotation for text i, h j i is the j th parse hypothesis generated by the k-best parser for text i, and f -score r (g i , h j i ) is the f -score accuracy of hypothesis h j i on the Relation metric.