A Relevant Passage Retrieval and Re-ranking Approach for Open-Domain Question Answering
Abstract
Question answering systems (QAS)s aim to directly return precise
answers to natural language questions. Retrieving and re-ranking passages are
viewed as the most challenging tasks in a typical QAS and still require nontrivial
effort. In this paper, we propose a novel approach for retrieving and reranking
passages using n-grams and SVM. Our n-gram based passage retrieval
engine relies on a new measure of similarity between a passage and a question.
The retrieved passages are further re-ranked using a Ranking SVM model
combining different text similarity measures in order to return the most relevant
passage to a given question. Our experiments and results have shown promise
and demonstrated that our approach is competitive.