DFKI-LT - DFKI-LT at QA@CLEF 2008

Bogdan Sacaleanu, GŁnter Neumann, Christian Spurk
DFKI-LT at QA@CLEF 2008
in: Carol Peters, et al. (eds.):
3 CLEF 2008 Working Notes,
Working Notes, Aarhus, Denmark, Springer Verlag, 2008

 
This Working Note shortly presents QUANTICO, a cross-language open domain question answering system for German and English document collections. The main features of the system are: use of preemptive off-line document annotation with information like Named Entities, sentence boundaries and pronominal anaphora resolution; online extraction of abbreviation-extension pairs and appositional constructions for the answer extraction; use of online translation services for the cross-language scenarios and of English as interlingua for language combinations not supported directly; use of redundancy as an indicator of good answer candidates; selection of the best answers based on distance metrics defined over graph representations. Based on the question type two different strategies of answer extraction are triggered: for factoid questions answers are extracted from best IR-matched passages and selected by their redundancy and distance to the question keywords; for definition questions answers are considered to be either the first sentence of description paragraphs in Wikipedia documents or the most redundant normalized linguistic structures with explanatory role (i.e., appositions, abbreviation's extensions). The results of evaluating the system's performance by QA@CLEF 2008 were as follows: for the German-German run we achieved a best overall accuracy (ACC) of 37%; for the English-German run 14.5% (ACC); and for the German-English run 14% (ACC).
 
Files: BibTeX, WorkingNotesCLEF08.doc