Early question-answering (QA) systems, such as Baseball (Green et al., 1961) and Lunar (Woods, 1973) were carefully hand-crafted to answer questions in a limited domain, similar to the QA components of ELIZA (Weizenbaum, 1966) and SHRDLU (Winograd, 1972).
there has been a resurgence of QA systems following the TREC conferences with an emphasis on answering factoid questions.