BioGrapher: Biography Questions As A Restricted Domain Question Answering Task

We address Question Answering (QA) for biographical questions, i.e., questions asking for biographical facts about persons. The domain of biographical documents differs from other restricted domains in that the available collections of biographies are inherently incomplete: a major challenge is to answer questions about persons for whom biographical information is not present in biography collections. We present BioGrapher, a biographical QA system that addresses this problem by machine learning algorithms for biography classification. BioGrapher first attempts to answer a question by searching in a given collection of biographies, using techniques tailored for the restricted nature of the domain. If a biography is not found, BioGrapher attempts to find an answer on the web: it retrieves documents using a web search engine, filters these using the biography classifier, and then extracts answers from documents classified as biographies. Our empirical results show that biographical classification, prior to answer extraction, improves the results.