“…Lee et al (2011) proposed a competitive non-learned sieve-based method, which constructs clusters by aglomerating mentions in a greedy manner. Entity-centric models define scores for the entire entity clusters (Culotta et al, 2007;Haghighi and Klein, 2010;Rahman and Ng, 2011) and seek the set of entities that optimize the sum of scores; this can also be promoted in a decentralized manner . Pairwise models (Bengtson and Roth, 2008;Finkel et al, 2008;Versley et al, 2008), on the other hand, define scores for each pair of mentions to be coreferent, and define the clusters as the transitive closure of these pairwise relations.…”