关键词: 术语抽取, 短语过滤, 左右熵, 活跃因子

Abstract: In the term extraction process，some phrases or phrase fragments containing active lexical represent as the noisy，which usually have the stable collocation pattern and a high co-occurrence probability in the corpus.The traditional phrase filtering methods are inclined to measure the cohesion of the inner words，and own less discriminate ability with these active noisy.This paper proposes a phrase filtering approach based on left/right entropy technology to evaluate the active degree of words in the phrases or phrase fragments and filter the ones having high value.Validated by the tests，this approach can effectively remove the active noisy and improve the performance of the multi-word term extraction system.

Key words: term extraction, phrase filtering, left/right entropy, active factor