Dependency-based answer validation for German
Svitlana Babych, Alexander Henn, Jan Pawellek, Sebastian Padó · Cross-Language Evaluation Forum · 2011
This article describes the Heidelberg contribution to the CLEF 2011 QA4MRE task for German. We focus on the objective of not using any external resources, building a system that represents ques- tions, answers and texts as formulae in propositional logic derived from dependency structure. Background knowledge is extracted from the back- ground corpora using several knowledge extraction strategies. We answer questions by attempting to infer answers from the test documents comple- mented by background knowledge, with a distance measure as fall-back. The main challenge is to specify the translation from dependency struc- ture into a logical representation. For this step, we suggest dierent rule sets and evaluate various conguration parameters that tune accuracy and coverage. All of runs exceed a random baseline, but show dierent coverage/accuracy proles (accuracy up to 44%, coverage up to 65%).