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DFKI-LT at QA @CLEF 2007

Bogdan Sacaleanu; Günter Neumann; Christian Spurk
In: CLEF 2007 Working Notes. Conference and Labs of the Evaluation Forum (CLEF), 2007.


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 anguage 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 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 2007 were as follows: for the German-German run we achieved an overall accuracy (ACC) of 30%; for the English-German run 18.5% (ACC); for the German-English run 7% (ACC), for the Spanish-English run 10% (ACC) and for the Portuguese-German run 7% (ACC).