MEASURING SEMANTIC SIMILARITY BY CONTEXTUAL WORD CONNECTIONS IN CHINESE NEWS STORY SEGMENTATION

摘要

A lot of recent work in story segmentation focuses on developing better partitioning criteria to segment news transcripts into sequences of topically coherent stories, while simply relying on the repetition based hard word-level similarities and ignoring the semantic correlations between different words. In this paper, we propose a purely data-driven approach to measuring soft semantic word- and sentence-level similarity from a given corpus, without the guidance of linguistic knowledge, ground-truth topic labeling or story boundaries. We show that contextual word connections can help to produce semantically meaningful similarity measurement between any pair of Chinese words. Based on this, we further use a parallel all-pair SimRank algorithm to propagate such contextual similarities throughout the whole vocabulary. The resultant word semantic similarity matrix is then used to refine the classical cosine similarity measurement of sentences. Experiments on benchmark Chinese news corpora show that, story segmentation using the proposed soft semantic similarity measurement can always produce better segmentation accuracy than using the hard similarity. Specifically, we can achieve 3%-10% average Fl-measure improvement to state-of-the-art NCuts based story segmentation.