Abstract: Single document question answering is also called Reading Comprehension(RC)，which attempts to understand a document and returns an answer sentence when posed with a question. We proposed an approach that adopted multi-strategy and utilized external knowledge to improve the performance of RC,including pattern matching with Webbased answer patterns,lexical semantic relation inference and context assistance. This approach gives improved RC performance on the Remedia corpus. The effectiveness of different strategy was analyzed and pairwise t-tests show the performance improvements due to Web-derived answer patterns and lexical semantic relation inference technique are statistically significant. In addition, the performance impact by the co-reference resolution was also discussed. Finally, the comparison between the task of RC and multi document question answering(QA) was analyzed.

Key words: Pattern, Reading comprehension, Question answering, Natural language processing