Pattern Optimization and the Application in Question Answering

Open domain question answering (QA) represents a challenge of natural language processing, aiming at returning exact answers in response to natural language questions. Recently, it has been found that pattern matching is an effective strategy for QA. The technique of pattern optimization and its applications in QA are demonstrated in the paper. Named entity recognition is used to optimize the answer patterns. It makes the answer patterns have better extending ability. There are two important applications of pattern in QA. Pattern-based query expansion retrieves more exact snippets including the correct answer and the performance is improved. Answer extraction which applies the pattern matching approach is also effective.