However, this step is still necessary for bootstrapping RE, since machine learning approaches require a sufficient number of positive examples to train the extractor.
(Yakushiji et al., 2005) 33.70 33.10 33.40 (Mitsumori et al., 2006) 54.20 42.60 47.70 (Erkan et al., 2007 59.59 60.68 59.96 our results confirm the observation that frequently co-occurring pairs of entities are likely to stand in a fixed relation.