The Ephyra QA System at TREC 2006

The Ephyra QA system has been developed as a flexible open-domain QA framework. This framework allows us to combine several techniques for question analysis and answer extraction and to incorporate multiple knowledge bases to best fit the requirements of the TREC QA track, in which we participated this year for the first time. The techniques used include pattern learning and matching, answer type analysis and redundancy elimination through filters. In this paper, we give an overview of the Ephyra system as used within TREC 2006 and analyze the system’s performance in the QA track.