Lymba's PowerAnswer 4 in TREC 2007

This paper reports on Lymba Corporation's (a spinoff of Language Computer Corporation) participation in the TREC 2007 Question An- swering track. An overview of the Power- Answer 4 question answering system and a discussion of new features added to meet the challenges of this year's evaluation are de- tailed. Special attention was given to meth- ods for incorporating blogs into the searchable collection, methods for improving answer pre- cision, both statistical and knowledge driven, new mechanisms for recognizing named enti- ties, events, and time expressions, and updated pattern-driven approaches to answer definition questions. Lymba's results in the evaluation are presented at the end of the paper.