Efficient Information Extraction Based on Signature Index

Information Extraction (IE) is an essential tool to retrieve structured information from at text (including web-content).Given a pattern query, an ideal IE application should be able to extract the matched target effectively and efficiently. However, as far as we know, efficiency and flexibility are major concern for typical IE tools since they either use brute-force document parsing for each query off-line or support on-line query in pre-extracted elements. In order to promote accuracy and efficiency of extraction, in this paper we propose a novel framework iExtractor that leverages In-formation Retrieval (IR) indexes to speed-up IE processes. We index text blocks with their signatures (presented as bit-strings) and propose efficient IE algorithms based on the signature index. Hence, iExtractor can validate query pattern in signature index without original text. The framework also supports on-line extraction through a general and flexible pattern extraction language. Our extensive experimental results on diverse real datasets show that our approach delivers stable efficiency and has outperforms baselines in terms of extraction accuracy.