As users struggle to navigate the wealth of on-line information now available, the
need for automated question answering systems becomes more urgent. We need
systems that allow a user to ask a question in everyday language and receive an
answer quickly and succinctly, with sufficient context to validate the answer. Current
search engines can return ranked lists of documents, but they do not deliver answers
to the user.
Question answering systems address this problem. Recent successes have been
reported in a series of question-answering evaluations that started in 1999 as part
of the Text Retrieval Conference (TREC). The best systems are now able to answer
more than two thirds of factual questions in this evaluation.