关键词: 问答系统(QA), 传统问答系统(TQA), 基于社区的问答系统(CQA), 信息检索, 答案抽取

Abstract: Recently, question and answering systems have attracted lots of attention. Given a question, the goal of question and answering is to return a concise, exact answer. According to the format of data, question and answering can be di-vided into three categories: the structural data based question and answering, the free-text based question and answering, the question-answer pairs based question and answering. This paper describes and summarizes the char-acteristics and related researches of these three categories respectively. Then, it discusses the future work of question and answering.

Key words: question and answering (QA), traditional question and answering (TQA), community-based question and an-swering (CQA), information retrieval, answer extraction