Answer Extraction from Passage Graph for Question Answering / 2169
Hong Sun, Nan Duan, Yajuan Duan, Ming Zhou

In question answering, answer extraction aims to pin-point the exact answer from passages. However, most previous methods perform such extraction on each passage separately, without considering clues provided in other passages. This paper presents a novel approach to extract answers by fully leveraging connections among different passages. Specially, extraction is performed on a PassageGraph which is built by adding links upon multiple passages. Different passages are connected by linking words with the same stem. We use the factor graph as our model for answer extraction. Experimental results on multiple QA datasets demonstrate that our method significantly improves the performance of answer extraction.