HITIR's update summary at TAC2008: Extractive content selection for language independence

摘要

The update summary aims to capture evolving information of a single topic changing over time. It delivers salient and novel information to a user who has already read a set of older documents covering the same topic. According to the new challenges brought by update summary, we propose the evolutionary manifold-ranking algorithm, and further integrate the sub-topics partition with spectral clustering to have a content selection, which is completely language independence. Three systems: 11, 41 and 62 are submitted. Our best system ranks three top 1 under average modified (pyramid) score, average numSCUs and macro-average modified score with 3 models of PYRAMID, ranks 13th in ROUGE-2, ranks 15th in ROUGE-SU4 and ranks 17th in BE. Though the evaluation results show the interesting performance of the proposed method, yet the problem is far from solved.