Ranking suspected answers to natural language questions using predictive annotation Dragomir R Radev author John Prager author Valerie Samn author 2000-04 text Sixth Applied Natural Language Processing Conference Association for Computational Linguistics Seattle, Washington, USA conference publication radev-etal-2000-ranking 10.3115/974147.974168 https://aclanthology.org/A00-1021/ 2000-04 150 157