TREC 2003 QA at BBN: Answering Definitional Questions.
Jinxi Xu, Ana Licuanan, Ralph Weischedel · Text REtrieval Conference · 2003
For definitional QA, we adopted a hybrid approach that combines several complementary technology components. Information retrieval (IR) was used to retrieve from the corpus the relevant documents for each question. Various linguistic and extraction tools were used to analyze the retrieved texts and to extract various types of kernel facts from which the answer to the question is generated. These tools include name finding, parsing, co-reference resolution, proposition extraction, relation extraction and extraction of structured patterns. All text analysis functions except structured pattern extraction were carried out by Serif, a state of the art information extraction engine (Ramshaw, et al, 2001) from BBN.